I just tried out MC 2.5A8, and the debugging is great! However, my machine has crashed twice. Also Cmd-O often tries to open a stack rather "Step Over" in the debugging process. And Cmd-F and Cmd-G do not work as they are supposed to in the script window. I am using a Mac under OS9.2.2. Is that the problem? Does 2.5A8 only work in OSX?