I recently upgraded from the 4 to the 5 and have an att Sim card from straight talk. I purchased a straight talk iphone 5 from walmart which is basically a verizon iphone 5. its Jailbroken with evasi0n 1.0 and I have the tether me app and have already edited all the apn settings. I basically did everything that i did before to get mms on my iphone 4 and it worked fine. well now I have literally tried everything, reseting network settings then re entering cellular data info then switching to airplane mode, then removing sim, then toggling cellular data on off. is there another way? or the fact that i have an att straight talk sim in the straight talk iphone 5, will it just not work like this? or would i get the same results if i had an att iphone 5. please help. and I have data just fine. just need mms