I wasn't able to send or open picture messages when I went from DroidMod to BB 1.0/1.1. I did NOT do a wipe when I switched between the ROMs. When I reflashed and formatted everything, I regained my picture message sending.
yah ive noticed that i have the same problem. i have wiped data and cache several times sense i noticed it first start happening. i tried switching to several different ROMs to see if it would fix itself, but never did. Kangerade, CVPCS, SS, pretty much all of them and still never regained the ability. not sure if i can recieve them, havent really checked that.
If you've done a baseband upgrade recently, that is most likely the problem. I too lost my ability once to send and receive MMS messages. My problem arouse right after I updated to what was suppose to be a better baseband. So I reverted back to the previous baseband and it seemed to fix the problem.