[HELP] Xperia M IMEI/IMEI SV Exclusion?

!!NEED HELP URGENT!!

So, I have a XM SS.
What I did is, took backup of TA before unlocking bootloader.

After unlocking, phone went in a soft brick condition. So I flashed stock ftf and luckly the baseband and imei got restored automatically.
(There was some notification about restoring TA on notification bar)


The problem start here,
I flashed twrp recovery and then wiped system+data+cache and flashed ROM.zip and wiped dalvic+cache and reboot.

Phone started normally and the ROM was beautiful. But the network said 'No Service'. Then I checked sim status and imei in settings, it says 'Not Available' BUT baseband was shown in the settings.

Then I again flashed stock firmware and the baseband+imei got restored automatically. (There was some notification about restoring TA)

Now I want to use this ROM+sim card. What should I do? Any ideas will be appreciated.

OR

Should I backup any other thing before flashing ROM. So that I can restore it after flashing. I have heard about backing-up imei file, will it work?

Any Help or Suggestion will be appreciated!
Thanks.



Regards,
hitman-xda