I have messed around a bit with the stock registry settings and have come up with a solution that allows you to receive images with a 20%~25% decrease in size. I have sent files as large as 1280 and it was resized to 922 width..
Here are the settings in the registry I changed. I figured since my other phone (the i760) had to still be in the verizon uaprof thing, I could possible figure out the values.
Here is what I came up with. Perhaps someone can find another phone that verizon supports that would have a larger screen and be capable of getting larger pictures.
I do have the dcd carrier cab installed, but I don't think that'll have anything to do with it.
This fix should not require the installation of anything other than a registry setting
Please give this a try
hklm\software\samsung\mms\settings\
UAProf
old value:
http://uaprof.vtext.com/sam/i910/i910v1.xml
new value:
http://uaprof.vtext.com/sam/i760/i760.xml
//attempt to masquerade as a different phone
useragent: (involved with above)
old value: sami910v1
new value: sami760
I have had success with this, while the cabs didn't work for me other than causing my phone to lock up. I do believe the useragent is what's messing with everything.. meaning *SHOCK* it is verizon. Can confirm that video works fine. Sent myself a 3gp video and it played in the message window, no errors.
**edit**
settings for the i760 were
http://uaprof.vtext.com/sam/i760/i760v1.xml
no useragent key
this setting seems to give the same results.. please test