:/..... ive been experiencing the same problem with sketchup 8 pro n im running it on my mac OS x snow leopard
if the files/projects exceed 120 MB they start crashing they crash occasionally wen u open them again they crash each time u try to rotate they crash wen u import something n they crash if u want to export the project on warehouse
they also crash wen u try to pan or edit poly/explode component or group. plzz i need help i need to know how to fix this problem... u can also mail me at knzarshad@gmail