I have 3G mobile broadband(Visiontek 7.2 HSUPA modem with AIRCEL simcard) which was very well detected and able to browse Internet in Ubuntu 12.04 previously.
Unfortunately I have installed V mobile broadband(bcm software) out of enthusiasm,after that mobile broadband is not being shown up in network manager.
Even after complete removal of V mobile broadband also 3G modem is not being detected.