I'm not a MAC genius, but I am a MAC lover/addict.

It could be anything. Are you on system 9 still, or 10 and which version if 10? I've had to delete the printer in the printer utility program and re-add it (On system 10. If memory serves, seems like in 9, I had to put it in the system library under printer prefs). That has helped before. You might also try throwing away the preferences from the applications you are having problems with (Put them into a folder on the desktop first just in case. The application will make a new default preference when you open it up after that.) Updating could help... do you have your system discs to reinstall the OS? You could start fresh so you can give yourself a password and get the updates. (Back up your files first though because if you do a fresh install, you will lose everything.)

Hope that gives some ideas. Good luck with figuring it all out.