Messages: Not sending, but receiving to iOS

[VideoBeagle]

I'm on Mavericks on my iMac.

Messages is not sending to a friend using Messages on her iPhone.
It worked fine yesterday.

I can send to her on my iPad and iPod Touch, and the messages go, AND show up in the Mac.

I can see her replies on the Mac.

I've tried signing in and out, deleting the preferences..nothing.
Tried sending to both apple ID and the phone number...nothing

Tested with another iMessage friend, same problem.

AIM chat is working fine.


Any one have any ideas on this?

 

[VideoBeagle]

And now it works with me doing nothing but trying hours later...so some problem on Apple's end?

 

[VideoBeagle]

And dead again...it's got to be an issue with Apple's gateway.