OK after alot of looking and reading this is what i've found and VERIFIED
family plans with unlimited texting work fine
any text plan should work
The Tricks and why:
the iphone was not setup for MMS messaging (DUH) we all know this but AT&T in their ultimate wisdom have desided since it dont do it we wont let you. This is the problem with no 1 set of parameters working for any length of time.
Work arounds:
Short term: I put my sim in my palm centro sent a few mms's to the wife took the sim and put it back in my iphone and configured swirly using mmsc.cingular.com , It worked flawlessly for a while and then started getting that unexpected error.
Long Term: I restored my iphone to firmware 1.1.4 then I used ziphone to fake my ieme number to that of my centro then I waited for for AT&T to do there snoop thing and now I send mms all the time with no problems and all other feathers work fine as well
Alternative: the fake phone setup a few have talked about might work it was just easier for me to fake the ieme number. I own both phones so I dont see the problem