MMS is working for me. Possible Sprint glitch at time of testing????
Short version:
Looks like I had to reflash .3, and then just restored apps/data through Titanium. MMS works now.
Long version, in case it helps anyone else:
1) Fresh v.3 - MMS not working
2) Nandroid backed up Fresh v.3
3) Wiped data/cache/dalvik - Flashed stock-rooted rom - MMS Worked
4) Wiped data/cache/dalvik - Restored Fresh v.3 Nandroid back up - MMS not working again
5) Wiped data/cache/dalvik - Flashed Fresh v.3 MMS working
6) Restored apps + some system data (like Sense desktop) through Titanium - MMS still working now