Ipod touch is suddenly not authorized to sync with my G5

My ipod touch has been synching without any problem until this past week end, when I got a message that "this computer is no longer authorized for apps that are installed on the ipod "Michel....'s ipod" Would you like to authorized this computer for items purchasedfrom the itunse store?" (if you do not authorize this computer, 18 apps and, including air hockey, .....and their data will be deleted from this ipod.) Then I clicked Authorize, but it doe not recognize my password.

my user name is mvezina1@mac.com.... and my password is inputed properly... but I get "there was an error storing your authorization information on this computer"... (the required directory ws not found or has a permissions error. Correct this permissions error and try again, or deauthorize this computer if the permisions cannot be changed).

Now, could it be that the @mac address has become a problem?? cuz when I go to iCloud, I use mvezina1@me.com.. and not @mac.

abnormality.

After 5 days of trying to sync the ipod, I synched it with the DONT authorize button in the dialog window. And now in my photos I have "photo stream" which I never had before!

So I am not sure if Icloud has anything to do with this??

Anyhow... in my sys prefs in my MAC G5 power PC (OS 10.5.8) in Mobile me, ( i know that Mobile me is gone June 29) my user name " mvezina1@mac.com" will not work anymore... so why did it work up till now, and stopped working last week end?

very puzzled!

Michel