[Q]Baseband become 'unknown' on all roms except stock and CM - Vibrant Q&A, Help & Troubleshooting

I have owned multiple Vibrants, but I can't understand the problem with this one specifically that I recently purchased. It seems to be farcical, but it is the case.
The problem: Beside stock and CyanogenMod roms, no matter what other roms I installed, whether it is Paranoid Android, SlimBean, AOKP, the baseband gets undetected either immediately after flashing, or while using the device. This is even if the /radio/modem.bin file is still exist with the correct permission and the IMEI is correct. After the baseband become undetected, the only way to fix it is to reflash a rom.
Example: I might be using the phone fine with baseband available and then suddenly it disappeared while the phone is turned on or after a reboot (which then means no more phone number, no more signal, call and data capability).
Exception: The only time the baseband stay put is with stock Odin image or Cyanogenmod rom. I don't know why specifically its okay with CyanogenMod roms. If I flash a non-CyanogenMod roms file that have modem.bin included within it, then it will not work, the baseband still goes missing, ie AOKP and Paranoid Android rom.
Things I have tried that doesn't fix the problem:
-Odin JDF or KB5 + repartition -> KB5 kernel & modem CWM patch -> CM7 -> ICS Passion -> CM10 -> SlimBean or AOKP
(immediately after flashing SlimBean the baseband is no longer detected, even though /radio/modem.bin exist)
(after flashing AOKP / Paranoid Android, the radio is detected, but while using the phone or after a reboot, the baseband goes undetected)
-manually deleting the modem.bin file from /radio, then flashing another rom that has modem.bin included (doesn't help, unless its CM10)
-fixing permissions in CWM
-Odin JDF -> Kies update to Android 2.2 -> CM7, etc.
-Switch between Froyo and GB bootloaders
-Switching sim cards
Other:
-I bought this one used, the IMEI of the device doesn't seem to match with the IMEI on the box that the buyer gave. I don't know if this means anything though.
-Also I don't know about EU bug, but this device can detect both internal storage and sdcard slot without problem, but could this be related?
-Could this be kernel related and is there any kernel recommended to flash?
Do anyone have an Odin image of just the modem that I can try flashing? I can not flash CWM modem patches to the JellyBean roms since the patches are only compatible with the older version of CWM.
I would be perfectly content with CM10 only in this device if I can figure out how to add the sliding brightness bar feature that is available from AOKP.