Multiple problems with Courtesy Accidentals

Not sure how to write up these properly (some involving problems of their own).

PROBLEM 1

1. Open attached score.
2. Add sharp to first crotchet.
3. Add sharp to second crotchet.
4. Add natural to first crotchet.
5. Click on the sharp of the second crotchet.
6. Delete.
(Result: Sharp is still there)
7. Delete.
(Result: Sharp is gone)

Using MuseScore 1.0 - Mac 10.4.11.

In MuseScore 2.0 nightly build (4156), I cannot go beyond 4, because it will not allow me to apply a natural (is this behaviour correct?).

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PROBLEM 2

1. Open attached score.
2. Add sharp to first crotchet.
3. Add sharp to second crotchet.
4. Add sharp to first crotchet.
5. Click on sharp of second crotchet.
6. Delete.
7. Undo.

Result: Undo doesn't work properly.

Using MuseScore 1.0 - Mac 10.4.11.

In MuseScore 2.0 nightly build (4156), this doesn't appear to be a problem as such (on the 10.6.7 MacPro - a different keyboard to the 10.4.11 MacBook - with regards to delete/backspace e.t.c, which I can't test because of rectangle features). I would recommend making sure though.

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PROBLEM 3

1. Open attached score.
2. Add sharp to first crotchet.
3. Add Sharp to second crotchet.
4. Click on sharp of second crotchet.
5. Delete.

Result: Sharp is still there (unable to select either) and collides with first crotchet.

Using MuseScore 2.0 nightly build (4156) - Mac 10.6.7.

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PROBLEM 4

1. Open attached score.
2. Add sharp to first crotchet.
3. Add sharp to second crotchet.
4. Undo.

Result: The third (and first to function) attempt to undo produces a step not originally taken (one C sharp crotchet).

Using MuseScore 2.0 nightly build (4156) - Mac 10.6.7.