*228 is an activation number you can call from your cell phone to program your phone with the most current settings with the cell toweres surrounding your cell phone. It is advised to do every other month or so in order to make sure your phone is going off the most up to date roaming information.
Typically with picture messaging issues, however, more t han a simple *228 programming may be requried. I would recommend that is *228, and power cycling your phone do not work, to take it to an in-store tech at a store or call technical support since there's other steps that can be taken in order to determine if it's your phone or something needing to be done in the switch.
This may be unrelated, but...
I had a Voyager with connectivity problems when receiving pictures and found that it was somehow linked to a GIN email app I had downloaded. I routinely check for software updates on all my GIN apps and found that one of them fixed this issue. The email app would constantly 'push' email to my phone, so the data connectivity was always 'on'.
In any event, checking for software updates is usually a good thing.
Another issue may that you have the "National Access Block" on the line which totally block all data transfers on the phone. Call customer service to have them check the blocks on the line.