One other thing to try that hasn't been mentioned yet is to log in to a test Admin user account and see if your issues follow you across account lines.
If you haven't got such an account set up you can do so in /Apps/SysPrefs/Accounts.
The new Great Equalizer is the SEND button.
In Memory of Harv: Those who can make you believe absurdities can make you commit atrocities. ~Voltaire
