Hello guys, i just succeded mobile data to work on CM9.0 - FXP107 FreeXperia Project rom. Here is how:
Just download from the market HiAPN Global "https://market.android.com/details?id=net.hidroid.hiapn.ml&feature=search_res ult#?t=W251bGwsMSwxLDEsIm5ldC5oaWRyb2lkLmhpYXBuLm1 sIl0".
Open the app.
Click on DNS Check, read the prompt and then press ok.
Go to bottom of the page and press change dns to write allowed.
After that deactivate transmitter ( it is the second button from the top of the same page, after the ping test ) and then again activate transmitter. After a few seconds you sould see the 3G icon over the signal bars.
Thats it, mobile data is on and running.
You may need to activate/deactivate transmitter on every restart.
Hope i helped you, and by the way, excellent work FXP, love my new phone.
For the Data fix
It would be a great idea to put this in the OP