This problem has been around for some time and I still see it in 2010 sp4.
Maybe it's fixed in 2011 I don't know.
I've opened a drawing from 2007 to delete a few unneeded parts. Sound simple enough. When I opened the assembly there were broken mates all over. So I updated the parts to 2010 and many mates repaired. Some of the mates I had to just open and close for them to solve and some I have to delete and put back in. Nothing unusual here.
I reviewed the drawing views and most things looked ok, I had to open each exploded view in the model and edit the exploded view lines to get them to update on the drawing because there were shifted off of the part.
I was just about finished with I noticed I had 2 balloons that had a 27 in them. The view was linked to the one and only BOM in the drawing. When I looked at the bom it had 2 item 27s in it. Different parts but in adjacent rows. The only way I could find to fix this was to delete the bom and put it back in. No big deal. The two 27 ballons didn't update until I linked it to the BOM. I then made sure the other 16 drawing views were linked to the bom to.
OK maybe the item 27 was a bug but when I put the new bom in why were the balloons still wrong? CTRL Q which I use thousands of times a day didn't do anything. Is there a was to update balloons on drawing views?
After going through this I thought I would add a couple of enhancement requests.
If there is only one BOM in the drawing all views should be linked to it.
If a view in not linked to a BOM DON'T show a balloon number. Put an * or a ? in place of a number. This would indicate that somthing is not right. Don't but a number in that is meaningless.
Looking through existing enhancement requests I notice SPR 558100 "Link balloons to specified BOM not ticked by default".
How is this going to help anything? Wouldn't this lead to the randomness that I'm seeing?
Maybe I don't understand how this should work. Can anyone explain it?