Straight Talk newer APN solution
Little disclaimer: Please note I only tested this on my T999 GS3 so please don't ask me for support on other devices. By following this thread you're responsible for your actions with your device.
I just want to share a little fix for those facing issues with data and MMS on Straight Talk with the newer
APN using AOSP. This may only apply to newer customers like me. I thanked the user that found the solution here
(more information there as to what I replaced with what). I changed two "Medianet" entries in /system/etc/apns-conf.xml to reflect the newer APN settings. Otherwise, MMS (and perhaps data) will not work properly (I could send MMS but not receive before this fix). I put the little file in a zip since XDA doesn't allow .xml uploads, it is NOT a flashable file
. Unzip, put the file permissions as rw-r--r-- using Root Explorer or your preferred choice, replace the file (again, located at /system/etc/), reboot and select the first MediaNet APN at Settings > More > Mobile networks > Access Point Names. Done.
A similar procedure can be done in a TouchWiz ROM, it does work. I tested it. You may or may not have to put in the newer APN at Settings.