AT&T 8310 MMS Issue

I have a blackberry 8310 that I am using with AT&T. Ive been using it for about 5 months now and it HAD been working great. Recently my MMS has not been working properly. When i receive a message it does not download. When I try to send MMS messages they will not send. However, when I do a battery pull it works fine directly after. Any ideas???

anyone..... =/

Just to check, you do have BIS service (a data plan, or all caps letters for your data (as in EDGE, not edge)), correct?

Correct. And my emails come in just fine, as do facebook notifications. it is just the MMS