problems sending pic MMS??

[kporter1500]

I've had my Intrepid for a few weeks now and I am having problems sending pics with MMS and downloading incoming pic MMS messages. I've had this problem ever since I got it. It's really weird because after I restart the phone, it has no problem sending MMS and downloading MMS. But after that, I could randomly send a pic MMS at anytime of the day and I get the error msg "Dialed: #777 no modem at above number. To check your connection settings and change them if needed, tap Settings." And it's crazy but the internet works fine. I tried to play around with the settings myself and I even took it into the Sprint store and it's still not fixed. Is anybody having this same problem??? What can I do???