iMessage on only receives texts on wifi

So I tend to use iMessage with my Dad on his iPad either with my iPhone 4 or ipad 4. Since he upgraded to iOS 7, I can't send him a message via iMessage. He's usually always connected on wifi and doesn't have 3G on his ipad (nor do I). The only time I can send him messages is when we are both on the same wifi network. I've tried to send him a few messages and they are just pilling up in my iMessage where it reads send 1 of 9 messages and the progress bar is jammed at about 1/5 of the way (with no timestamp beside the texts since they aren't getting delivered). My other contacts work so I'm thinking its on his end.



Any ideas? Muchas Gracias

via ehMac.ca http://www.ehmac.ca/showthread.php?t=111474&goto=newpost