Since re-installing my Lucid, I've had problems with some Wine apps (such as Hot Potatoes), which seemingly wouldn't run properly. Initially I thought this was because I was using the older Wine 1.1 which comes with the OS, so I added the ubuntu-wine PPA and updated to 1.2, but that didn't solve the problem. Realizing that the whole Wine tree had been backed up from my previous OS home dir and restored unchanged to the new one, I figured the problem might be something to do with stored settings such as window sizes and positions, so I ran regedit.exe under Wine and deleted all the registry entries for the affected programs. The problem went away. Just noting this in case we come up against it again.