Cannot copy individual rest

1. Create 4/4 piano score.
2. Create crotchet and quaver rests.
3. Copy a crotchet rest.
4 Paste it onto a quaver rest.

Desired result: The rest copies and pastes.
Actual result: Nothing happens.

Using MuseScore 1.0.0 pre-release 2 (3949) and Mac 10.4.11.