Yes. I have tried changing baseband (modem) alone (flash - reset - flash - reset) and I can see in the phone's options that it has changed, yet the phone behaviour stays the same.
Is it possible that I have physically broken something by multiple re-flashings or swapping the sim cards? I mean someone suggested that this is problem with SIM port but this seem unlike as the phone should still be able to connect emergency calls, shouldn't it?