General instability: how to troubleshoot and fix?
Word seems to be the most unstable. It actually works fine, for the most part, but even during ordinary use I will often get the message that the application is not responding when I click on the icon. Usually I can use drop-down menus to keep on working--creating new files, and so on. But still it must be force-quit at the end.
Often when I have a number of windows open, the system will take a long time to respond to requests, delaying a "close window" command by 30 seconds, for example (with spinning ball).
I've repaired permissions, including booting from the OS X disk. I've also run repairs using diskwarrior, and inspected the hardware.
How can I troubleshoot and fix this cross-application instability?
iMac Alum 20", Core 2 Duo, 2GHz, 3 GB / Macbook (2010), Mac OS X (10.6)