GSM/UTMS band choice

[Guest wrxppp]

I've been having problems with 3G voice calls dropping out since the 24th Nov (see other threads).

I'm not sure if its related to moving up to Radio 1.20 ROM shortly before then?

I've noticed in Phone>Band>GSM/UTMS band choice that there are 2 options:

GSM(900 + 1800) + UTMS(2100)

and

GSM(1900 + 850) + UTMS(1900+850)

My original Radio was 1.13 but I never looked closely at the band set-up menus as I never had any 3G call problems since i had the VAR II in 2 months.

What do these options relate to and wouild changing them help in overcoming voice call problems?

T MOb are telling me to force the Band selection to GSM only to stop the problems, which works but why should I need to if 3G was working fine some weeks ago?

nick