I cant tell exactly what causes it but as you cycle through a sidechain positions using the keyboard it will crash should be easy to replicate.
I suggest just mashing the arrow buttons on a few side chains till it crashes. shouldn't take more then 5 mins.
Yep, you're right. I presume this has something to do with the Selection Interface?
Windows 7 error log:
Faulting application name: Foldit.exe, version: 0.0.0.0, time stamp: 0x4e761405
Faulting module name: game_library.dll, version: 0.0.0.0, time stamp: 0x4ecafe77
Exception code: 0xc0000005
Fault offset: 0x008136da
Faulting process id: 0x1994
Faulting application start time: 0x01ccac1204ccf480
Faulting application path: C:\Program Files (x86)\Foldit\Foldit.exe
Faulting module path: C:\Program Files (x86)\Foldit\cmp-binary-5dae2de7da95a25528d26f65c401e6dc\game_library.dll
Report Id: ffc03172-183d-11e1-83eb-00a0d5ffffae
Seconded (or thirded), reported this a while back as well. It was only giving me trouble on guide puzzle though…