[runkittyrun]

mabey i missed this but i didn't see anyone suggest deleting the profiles on the phone, start active sync on your phone and go to menu>options, then highlight the computer name and select delete, clear all listed connection sources, (just make sure highlight the computer name and not the individual options so the delete button doesn't grey out)

also you can delete the mobile device from the computer under file>delete mobile device, but you said you tried this on other ocmputers so i would suggest clearing the settings on the device and try that, i had connection issue with active sync and clearing the device saved sync settings fixed it