I don't believe it is a driver issue. The first thing you need to do is install terminal emulator from the play store and enter the following:
If, and ONLY IF
it says you are on NE4, try flashing the NE4 modem. You can get it from my post here: http://forum.xda-developers.com/show...php?p=53627484
If you are on any other firmware build, find and flash the modem thst matches that build. (If the getprop command says you have MJB firmware, flash the MJB modem)
If you still have problems, flash the same firmware as you currently have via odin and factory reset. Backup first though!! This will wipe all your data including the internal sd.
(DO NOT FLASH OLDER FIRMWARE!!!! Only the same or newer as what you currently have!)
Explanation: if you have an incompatible modem installed, it will usually show unknown for your baseband and imei. This can also cause the EFS folder to appear blank. The reason your media won't play is because drm content relies on the contents of the EFS, so if its blank/cant be read, most media will not play.
Also if the wrong modem is installed, it will not be able to read your SIM card.
If after flashing the modem, and the full firmware you still have these problems, and your IMEI is not properly showing, PM me and I can help you further.