We have a very large drawing (112MB) that was created using AutoCAD 2007, and saved as the 2004 DWG type. The drawing is a processing plant that is being installed at our facility and it's largely done in 3D. Most of our users are using 2007, another drafter and I are using 2008, and we still have a few people on 2006. well, 2007 and 2008 won't open this drawing (even crashes AutoCAD), but the computers are more than capable.
P4 3.8GHz
4GB RAM
Quadro fx 3450 (256 MB) video card
However, anyone using 2006 (and the only person with 2004 in the whole plant) can open it easily. It takes a little time because the file is huge and the computers are older, but the drawing can be worked with from these machines without crashing.
What's up with AutoCAD 2007/2008 that makes it screw up so badly? Help Me! I'm going crazy trying to figure this out.