Strange MMS issue

[Guest kugeln]

Just flashed my unlocked SMT5600 with an Orange v4.2.5.2 ROM. Everything seems to be working great, except for the MMS function.

It's got some kind of restriction on it where it won't take an address shorter than 5 digits. I'm on T-Mobile in the US and they provide some services that use MMS and 3 and 4-digit addresses to upload images/video/sound to a 'my journal' type thing.

Any clues how to fix this?