2007.3 == Buggy and really unstable
On our experience the dramatic stability change started on 2007.5 update 5 onwards (several months in production without any stability issues or a single crash)
But if you are going to move, change to 2007.8 with a lot of bugs removed and improved functionality in some areas.
Here we did the validation and now is in production without any stability issues (a few bugs but nothing serious)
Indeed 2007.8 be stable than previous versions, but the unstable is continuing. Additionnally, some of thermal ties will be broken when a 2007.2 design be opened in 2007.8. If your design is small and there are less plane types, you may not encount this symptom. But for complex design where having hundreds shapes, you will find ties broken and broken places changed when you have fixed it and opening next time. Sometimes, Harzards checking can't check it at
all. I think we only can get a stable version after 2010.
For frequent crash during operation, following tricks may be helpful:
1) delete all MGC, Mentor Graphics, MentorGraphics items in Windows's register table.
2) check your path to see whether an old version's path be included.
3) slow your manipulation speed.