Spotted a severe issue of wild playback rate changes when moving a region or deleting a time signature marker. Affects audio and midi takes differently, and doesn't happen with a cropped take. Only happens when a region is moved to one direction, not the other. Timebase selection of the track or project has no effect.
Here's the link to the bug report. Tried to write in an organized manner, but it's a bit hard for this one:
http://forum.cockos.com/project.php?issueid=3489
Happens on 4.02pre3, 4.01, and 3.78. Not the correct place to report, but I find this to be a very severe issue.