ARocker, I don't know what Infamous did but all my backups didn't work with TWRP 2.5 and 2.6, after installing T-Mobile UVUAMDL, rooting and installing TWRP 2.6 all my MPCS backups started working but without WiFi with a pop up window saying: prevention information the device has detected an application attempting unpermitted actions and has stopped loading. To protect your device it is recommended you reboot.
Reading XDA forums found users with the same error when updating from UVUAMDB
to UVUAMDL and trying to root. The fix was to install UVUAMDL firmware, then UVUAMDB kernel with SetUID Restriction Removed.
The big deal with Metro is that when you install T-Mobile firmware there is something in the kernel that is never removed when you wipe data/system/cache/dalvik. You can run a Metro backup and everything works except WiFi and that is because of the T-Mobile Kernel is still there, then I did the same fix, over my restored metro backup I installed the UVUAMDB kernel with SetUID Restriction Removed and BANG! Wifi started working. What is funny is that when you do another backup restore with different restore point you need to install again the SetUId kernel fix again. That’s why I’m sure that is something with the kernel that is never removed/wiped even when you run a TWRP restore.
Now I have a rooted Metro Galaxy S4:
Device name: SGH-M919N
Baseband version: M919UVUAMDL
Kernel version: 3.40 matt@batakang #2
Thu May 1918:00:21 PDT 2013
With all features working on MetroPCS