I think I just found a new bug, I managed to do it three times in a row. I'm working on my avatars, so I've got attachments on my av, and I'm in edit mode with them of course.
So I'm editing an attachment, you know, while I'm wearing it. If I attach another object that goes on that attachment point, SL crashes. Well actually it locks up, I have to close it manually.
I'm using Windows XP SP2.