Failure sending Iphone International MMS

I have the Iphone 3G 3.1. I have yet to been able to send MMS messages overseas from the US. (More specifically to the Philippines) I have been on the phone with AT&T and Apple technical support. So far; no luck. I can send and receive MMS fine here in the US. Oddly enough, I can receive MMS from my friends in the Philippines. Again, for some reason, my MMS do not make it through to them even though it shows as being sent from my phone.

Prior to my Iphone, I had the LG Shine through AT&T and I had no problems sending or receiving MMS stateside or overseas.

Is anyone else out there having this problem or even tried to send an MMS internationally? I am attaching a blog from another Iphone user that is apparently having problems trying to send his MMS to the UK.

http://appmodo.com/5057/international-iphone-mms-fail/

Is Apple or AT&T blocking outgoing MMS to overseas phones? Is Iphone MMS messaging restricted to only stateside? Can anyone help?