Creating triplet in grace note leads to time corruption

MuseScore 0.9.6.3 & trunk (r3774)

1. Create a flute score in 4/4
2. Add a 4 quarters
3. Select the thrid quarter and add a quarter grace note
4. Select the grace note and go to Notes -> Tuplets-> Triplet --> Trunk crash here
5. The triplet is made with the actual third quarter note and not the grace note
6. Undo --> The measure just loose its third beat