MMS issues with 4S on 6.1

[tiffy255]

I've had issues with mms since I got this phone about seven months ago. I can send mms over iMessage, but that's about it. Can't send them to people with older iPhones or with other smartphones.
I've downloaded a few apps from cydia, and they haven't solved the problem. My phones jail broken and unlocked, and my carrier is H2O, with the profile installed using the unlockitz program (I can't remember if that's what it's really called), and there is no way I can get the cellular data tab in my settings to possibly change the proxy settings.
Any insight, even if its to tell me that I'm s.o.l would grateful!
Thanks!

 

[willerz2]

See if turning off iMessages resolves this issue.

 

[tiffy255]

I turned off iMessage an shut my phone off and turned it back on just to make sure the changes took, and still nothing :/