help! itunes constantly unable to detect my itouch.

i know theres a help page for this but it does not work.

the only way to get itunes to detect is to uninstall all its components and download & reinstall itunes.

then it can detect alright the next time i plug in. but just for once!

the 2nd time i try the same problem occurs again! needless to say its quite a hassle to reinstall itunes and restart my com everytime i wanna sync stuff. does any want have such a problem? if so any advice?

furthermore, how i can deauthorize all the computers from using my account in itunes store? i tried following the instructions but everytime i do that itunes just tells me it "cant access the store" so deauthorizing is not possible and should be attempted again later (error message). its driving me crazy.