"Got the very same problem yesterday.
After upgrading my RAZR I from stock 4.0.4 to 4.1.2 IMEI was changed from 35<something> to 004999010640000, which is exactly the same IMEI number topic starter has in his phone. And I have the very same problem with radio module - phone can not connect to GSM networks.
Phone originated from UK, was not rooted/unlocked and built-in over-the-air update was used.
Update: Resolved by re-flashing radio partition.
For some reasons latest 4.1.2 firmware distribution for my XT890 (Retail GB, 91.2.29001, CFC_9.8.2I-50_SMI-29_S7_USASMIJBRTGB.xml.zip) does not contain "radio_signed" part, so re-flashing latest firmware can not help with restoring IMEI.
I've used "radio_signed" file from 4.0.4 intermediate firmware update (81.5.39001, CFC_8.7.1I-110_IFW-39_S7_UCASMI01E1017.0R_USASMIICSRTGB_P042_A005_S1F F_fb.xml.zip).
After I've got a valid "radio_signed" file all that it took to repair my XT890 was a single command "fastboot flash radio radio_signed".
After flashing and rebooting IMEI number was restored to original 35<something> and I was able to connect to GSM network.
Boot loader is still locked and phone is not rooted, so this fix will not harm your warranty, if you still have any."
