Facetime Server Error

Hi all,

I am trying to log in to facetime on my iMac. I get "the server encountered an error processing registration. Please try again later."

Last year i changed my apple id from an old email to a new email due to change of work. It still worked. And just after christmas 2012 i did a complete reinstal with the apple disks that came with my imac. since then i have had this issue, i can use facetime on my ipad and ipod touch as they have had no effect.

I have also checked online to make sure my Apple ID is verified and it is.

thanks in advance for any help offered.

Greg.