unbeaten

hi frnz pls help me... am using reliance netconnect card ZTE MG 880 usb modem.. when i connect to the card, am getting some signals for some time and suddenly goes to 0 kbps and remains in zero for some 5min and becomes normal... but after five or ten min it again becomes zero,,, this occurs all time.... but the signal bars are full... am using vista os.. i complained to them about this but am not getting my solution,, am using netbooster too but no use.... pls help me frnz.. i believe on u..