I am using ChemDraw 3.1, and I am running under System 6.0.5 - System 6.0.7. When I try to launch ChemDraw, I get an out of memory error, even though I have allocated more memory to the application.
Systems 6.0.5 - 6.0.7 use 32-bit QuickDraw. If you have this extension installed, you must turn it off because it conflicts with ChemDraw. This can be done in the extension manager or the startup manager.