MrG:
I had this problem today for the very first time. (which is reported by others, elsewhere on this forum, several times (I think))
Windows Me, laptop, 192 MB of RAM... first time the system's ever been cleaned (by ANYTHING)... the CCleaner progress bar must have gone to 100% about 15 times before it crashed (MSVBM60.dll). It's Windows Me, so of course it doesn't tell you anything useful when applications crash, unlike Win98. I then emptied %temp% by hand and then CCleaner finished instantly (deleted 4 MB) and stopped crashing. Not sure what relation it has to anything, just thought I'd throw my notes in here.