Wondering if anyone has made the transition to 64bit? We recently added our first Win7 64-bit computer. Machine runs great, except AC inexplicably crashes about once an hour (no pattern on function being used, and often with no one even at the machine). Tech support says its the machine, but no other software has any problem. We "repaired" AC, uninstalled/reinstalled, same problem. No real error message given, just that the program has stopped working. Originally, it was a Win7 64bit Home Premium. Did an upgrade to Win7 64bit Professional, without any effect. Concerned because all the new machines available are 64-bit.