Well, could you try to disable some packers to see if it helps?

Would you be able to create and upload a full-memory dump at the moment when the computer is frozen? The description of the process is here:
http://support.avast.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=71
Notes:

  1. It works with PS/2 keyboard only, not USB
  2. The dump is rather huge (as big as your RAM size)