Cannot add phone number to Yahoo Messenger

[WreakingHavoc]

I get a error that says "Invalid Number" when trying to add my iphone cell number to Yahoo Messenger. Also I have installed the iPad YM app and when I try to send a SMS to a contact I get the same error message. I have installed the PC client and tried to add the number from that and when logged in to the Yahoo site under Preferences but no luck. I live in Canada and am on the Rogers network so based on the info on the Yahoo site it should work. Has anybody had the same problem and were able to resolve it?

Thanks.