1. Open or create a drumset score
2. Add some notes using mouse (use same process as described in handbook)
3. Click and hold the heading for the "Drums" palette. Choose "Enable Editing"
4. Swap some palette items around in the drums palette
5. File > Quit
6. Open or create a drumset score
7. Attempt to add notes using mouse (same process as described in handbook)

Expected behavior: Drum note entry should work in step 7 like it did in step 2

Actual behavior: Drum note entry in step 7 does not allow you to select an item from the "Drums" palette

Workaround: Quit MuseScore, delete the custom palette file (on my computer it is located at C:\Documents and Settings\USERNAME\Local Settings\Application Data\MusE\MuseScore\mscore-palette.xml ), then start up MuseScore again.