Default [Q] Signal Problems

Hi guys,
I really need some help!!!

I live in Europe and I got the G2X as a present from the USA for about two years now. I unlocked it and it worked fine.

But this Summer I noticed that I cannot change network when I am abroad. Before that it didn't happen I could change any network I wanted in different European countries. But since this Summer I could use only my home network.

About a month ago I couldn't make or receive any calls when I change base station within my own network. As long as I stay within one base station it works, but if I move around town and i change base station, no more calls... I would have to reboot the phone to be able to make calls. But no indication on the phone that there is any network issue at all.

I tried to change different ROMs, I changed the baseband to the march 2012 but unfortunately nothing works.

I also tried to experiment with network time settings but no result at all.

Any advice...? ((