BSNL 3G signal disappears in WCDMA Mode (samsung omnia windows mobile)

Hi Ricky..I have a samsumg omnia b7320 and on selecting the WCDMA option from the band selection after which the 3G signal appears for a few signal and after that all the signals (even the normal signals dissapear)..please help

This is because you don't have 3G coverage in your area or you are not allowed to use 3G. Actually signal doesn't disappears but when you switch from 2G to 3G, 2G signal remains visible for few moments and that is you are thinking as if signal disappears after few seconds.