mobile me problems

For some reason I am getting the following error from iCal:

THE SERVER RESPONDED WITH AN ERROR
The server did not recognize your user name or password for account "[email protected]." Make sure you enter them correctly.

what does this mean and where do I enter the password for mobile me. Its worked perfectly for the last year.

Please help.

Antony

Go to System Preferences, Under Internet & Wireless you will see "Mobile Me" icon.
Select it and you see a Tab named "Account". Check to see that your information is filled in correctly. You may even have to sign out and then sign back in.

Hope this helps.
DavidH

David, i did that it did not help, PLEASE any other ideas

Thanks