yahoo IM or SMS in the Philippines I get (receive) a lot of text messages from the Philippines via computer (SMS). Why am I being charged for an international text rate when the messages i receive comes from a computer and not from an actual cell phone.

I have an AT&T wireless account with 1500 messaging included. I also have a Yahoo IM which everytime i log off i get automatically log in to my cell phone as "I'm mobile" showing on yahoo IM. I am told by an ATT customer service rep. that everytime I receive or send messages to and from an international country i get charged for an international text rate. I mean, shouldn't i be charge for a standart text rate since the text messages isn't being sent from an actual cell phone number ?