You also did not say how big the files are. It is possible that you have some bogus objects or other elements that are causing problems in specific files. I usually discard the PowerCadd Prefs file whenever something ugly happens, like a crash, and restore from a backup file. If you don't have backups of the Prefs and the Commands, you should. Our machines have 224 megs of ram and we leave virtual memory 'on'.
Some applications seem to run better.
When I see crashes related to clicking somewhere outside the drawing window, I suspect an extention that is causing problems. It is good is to have a backup partition or an additional hard drive that has nothing but a 'virgin' system and an intallation of PowerCadd. This way you always have a way to keep working, and you can isolate the problems. Hope this helps. This document is provided for on-line viewing only.