Changing key signatures results in notes on C and D staff positions having same pitch

OS: Windows 7 Home Premium; Product ID: 00359-OEM-8992687-00010.
HW: AMD-A4-3300M APU with Radeon HD Graphics 1.90 GHz.
Memory: 6.00 GB
System Type: 64 bit
Model: HP Pavilion G7
MuseScore Version: 2.0.2; Revision: F51dc11.

This happened as a result of trying to figure out what key someone else was playing in, as I prepared to write some accompaniment. An empty score was gen'd from a previously made template that contained six instruments, as show in the accompanying test file. A number of steps of switching key signatures occurred before the problem became apparent, so I'm sorry that I don't know at which step the underlying file became corrupted (if that is what happened).

Notes:
All note changes were made to the violoncello stave.
Before beginning, load the furnished custom template to MuseScore 2: PitchTest Template.mscz

IMPORTANT NOTE 1: The below steps were used when the bug initially presented. The bug results were then accidentally reproduced by simply creating a new score based on the test template, selecting F sharp major in the Create Score Dialog box, and copy/pasting the final five notes from the test score into the newly created score. This might be a debugging clue.

IMPORTANT NOTE 2: Another debugging Clue --> Entering new notes into a fresh score created with the F sharp major key signature results in pitches that are different from both the furnished test score and the pasted test score. It seems that the key signature of the test score might have been somehow corrupted.

Test Script

Create a new score using the furnished test score template:
Step
1. Select File\New
Result: A popup dialog screen appears for creating a new score.
2. Give it title, any title, and select next.
Result: The title is accepted, and the dialog box moves to the next screen.
3. From the Templates screen, in the Custom Templates section, at the bottom of the dialog box, click on the custom template that was loaded for this test.
Result: The template is accepted, and the dialog box moves to the next screen.
4. The Key Signatures screen is displayed, with the default C Major (no sharps, no flats) highlighted. Select the button at the bottom right of the dialog box.
Result: The C major key signature is accepted, and the dialog box advances to the 'Create Time Signature' screen, where the time signature, along with pickup measure and Number of Measures int the score can be entered or selected. Default values are displayed.
5. Select the button at the lower right hand corner of the dialog box.
Result: An empty score is created, using the template.

Edit the score:
6. Select the quarter note icon in the top left interface.
Result: the quarter note icon is selected.
7. Select the note entry icon.
Result: the note entry icon is selected, the system is put into note entry mode, and a quarter note is ready to be added to the score.
9. In the first measure, click the first rest position on the B staff position (middle of the violoncello staff).
Result: A quarter note is added to the B line, at the beginning of the measure.
10. Click and drag to move the note up to the closest D staff position.
Result: The note is moved to the D line.
11. Select the sixteenth note icon.
Result: The icon is selected and a sixteenth note is ready to be added to the score.
12. In the first measure, directly after the first note, click in the A staff position, directly below the middle line on the staff.
Result: A sixteenth note is added to the A staff position, following the first note.
13. In the first measure. click on C staff position, on the rest following the second note.
Result: A sixteenth note is added to the first measure, following the D and A notes.
14. Press the keyboard button, to exit note entry mode.
Result: note entry mode is exited.
15. Click on the second note (A), to select it.
Result: The note is highlighted.
16. Click on the eighth note icon, to change the sixteenth note to an eighth note.
Result The sixteenth A note becomes an eighth A note, and the third note (C) is replaced with an eighth note rest.
17. Click on the new eighth note rest at the C position, on the middle of the Staff.
Result: A quarter note on the C staff position is inserted.
18. Click and drag the newly created C note, and drag it down to the B line staff position.
Result: The note is moved to the B line staff position.

19. Use the menu item, View\Pallets, display the pallets.
Result: The pallets list is displayed on the left hand side of the screen.
20. Select the 'Key Signatures' pallet to open it.
Result the 'Key Signatures' pallet opens, to show the Key signatures list.
21. Click and drag the C flat major (7 flats) icon to one of the staves, and drop it somewhere neat the time signature.
Result: All staves in the score are converted form key signature of C to C flat major.
22. Delete the flat accidental from the third note.
Result: The B flat note becomes a B note.
23. Delete the flat accidental form the second note.
Result: The A flat note becomes an A note.
24. Realize this is not the correct key signature.
Result: hit your self in the head.
25. Click and drag the E major (4 sharps) to one of the staves, and drop it over the existing C flat key signature.
Result: All score staves are converted from C flat to E major key signature.
26. Delete the flat on the second note (the A note).
Result. The A flat note becomes an A note.
27. Delete the flt on the third note (the B note).
Result: The B flat note becomes a B note.
28. Click and drag the second note (A) down to the closest G line on the staff.
Result. The note is moved to the G line.
29. Realize this is still not the correct key signature.
Result: Do nothing to harm yourself.
30. Click and drag the F sharp major icon in the pallet key signature list to the staff, and drop on the existing E major time signature.
Result: All score staves are changed to the F sharp major key.
31. Realize this is still not the correct key signature, and click and drag the C# major icon to any stave, and drop over the existing time signature.
Result: All staves in the score are converted to the C# major key signature, and a natural accidental is automatically assigned to the A note.
32. Click the A note natural accidental, and press delete on the keyboard.
Result The accidental attached to the A note is deleted.
33. Click the third note (B) to select it.
Result the B note is highlighted in blue.
34. Click the sixteenth note icon in the menu interface.
Result: The eight note B is changed to a sixteenth note.
35. Click on the Note Entry icon in the menu (top left) to convert to note entry mode.
Result: Note entry mode is entered.
36. Click on the rest following the third note on the staff to enter a sixteenth note on the D line, just above the middle of the staff.
Result: A sixteenth note is addded as the forth note, on the D line above the middle of the staff.
37. Click on the rest following the fourth note, on the A staff position (just below the middle of the staff), to add a fifth note.
Result: A fifth note is added to the A position of the staff.
38. Click and drag the just added fifth note to the C position of the staff.
Result: the note is moved to the C position.

Note: At this point, the score should look like this: Zombi_PitchTest_20160424_0 1A.mscz

39. Click the fourth and fifth notes (D and C notes), comparing the pitches.
Result: The pitches sound the same.

Try some things to see if the pitch problem can be easily fixed:
40. With the note still highlighted from moving it, press the keyboard delete key to delete it.
Result: The fifth note (C position) is deleted.
41. Click on the rest following the fourth note, on the C staff position, to re-add the sixteenth note to the C position on the staff.
Result: The sixteenth note is re-added as the fifth note on the C staff position.
42. Click the fourth and fifth notes (D & C notes), comparing the pitches.

Result: The pitches sound the same.

43. Click and drag the C key signature from the pallet, and drop on one of the staves to convert to the C key signature.
Result: The key signature is converted to C major (no sharps, and no flats).
42. Click and drag the C sharp major icon from the pallet to one of the score staves, and drop it.
Result: The key signature is converted back to C sharp major.
43. Click to select the fifth note (C), and hit the keyboard key, to delete it.
Result: the fifth note is deleted.
44. Add a fifth note back to the C position.\
Result: A fifth note is again added to the C position.

45. Click the fourth and fifth notes (D & C notes), comparing the pitches.
Result: The pitches still sound the same.