roaming indicator flashing

[tp2userp]

I am running FRX07 full time on Rhodium 400 with SIM on a GSM network. Its a great build and everything mostly works but I have a peculiar problem, no sure others have noticed it or not, I could not find it in the release thread. Any way, usually the phone wireless mode is 'WCDMA preferred' or one of the GSM modes, but when I move in to an area with no coverage, the phone AUTOMATICALLY defaults to CDMA/EVDO mode, and predictably the roaming indicator starts flashing or the network defaults to XDAndroid, and when I move back in to coverage area. Does any one know if this auto default to CDMA/EVDO can be stopped and if yes how to stop this mode change?