I have an assembly with several parts in it. I have created an assembly sketch (with no external references) that contains general sketch geometry, as well as 4 sketch blocks that I have created. I have the sketch blocks related to fully defined like I need them. I edit one of the parts and derive the assembly sketch into it. Everything is fine. The derived sketch contains the sketch geometry as well as the blocks. Later I need to edit the assembly sketch and reposition the blocks. The derived sketch updated like it should have.. Good... I had to edit this assembly sketch, as well as editing the blocks, on several occasions as I am planning my layout. During one of these edits, the derived sketch in the part went crazy. The sketch blocks did not update to their correct location, but the rest of the sketch geometry did. And, the derived sketch had the 'ol rebuild lights on the feature tree, which a ctrl-Q would not cure. Luckily, I had not created any model geometry referencing this derived sketch yet, so I tried to delete it and re-derive it. I got the same thing all over again, rebuild lights and everything. So, just to experiment, I tried to derive that same sketch into another part in the assembly. Everything worked great. Resizing the assembly sketch updated the derived sketch in the second part correctly, but still not in the first part. No matter how many times I delete the derived sketch out of the first part and try to start over again, I get the same problems.
Anyone got any clues here?