No cautionary time signatures when changing between two different time signatures of the same note value

My System:
Ubuntu 10.04
MuseScore Revision 2949M

The bug:
When there is a change of time signature between two time signatures of the same note value (ie 4/4 and 2/2) at the end of a system, a cautionary time signature is not displayed.

To reproduce:
1. Create a new piano score in 4/4
2. Put a line break at the end of the first bar
3. In the second bar, add a 2/2 time signature

Expected result: there is a cautionary time signature at the end of the first system reading 2/2
Actual result: there is no cautionary time signature, only the time signature at the beginning of the next system.

Attached is a file demonstrating this with two different time signatures.