I couldn't get MMS to send when I went to Froyo X.... untill I added a little bit to the apn I made for MMS.
It is frustrating, because when I tested it, the MMS went through fine, and when I had my friend send one back to me, the signal bar went from 3G to E, so it IS registering in some fashion that it is receiving one but it never does show up on my phone and then my signal bar goes back to 3G.
Anyways this is what my apn looks like to recieve MMS.
Name= Verizon
APN= internet
MMSC=
http://mms.vtext.com/servlets/mms?X-VZW-MDN=(your 10 digit phone number, without these brackets)
MMS Proxy= 80
MCC= 310
MNC= 995
APN type= mms
everything else was left alone.