Here is how I was FINALLY able to get VZW MMS working on the latest 21885
1) Installed:
MMS Fix (M2.5) (Verizon) (Valkyrie).cab
2) Changed server to: http://mms.vtext.com/servlets/mms?X-VZW-MDN=<your ten-digit phone number>
3) Changed WAP to "none" !!