Extraneous rests problem in irregular bars

I've come across a problem with MuseScore sometimes adding an extra crotchet (quarter note) rest to some bars defined with an irregular number of beats in the Measure Properties dialogue.

ie if the regulare time signature is defined as 4/4 and then you define the actual time signature for the bar as 7/4 MuseScore adds an extra crotchet rest to the end of the bar you are working on (thus making it 8 quarter notes to the bar not 7) which causes problems in the other staves in the system.

I have not been able to produce a sequence of actions which repeats this error yet, but was wondering if anyone else has come across it.