HELP!!!!!!!!!

i m using nokia 3105 cdma tata indicom. I ve downloaded the pc suite v. 5.22 correctly installed the drivers and using my phone as modem perfectly. but the moment i start the application or the nokia connection manager it shows "data connection ended" on my cell. please help. I m connecting my phone on com3 usb-serial port. other phones work perfectly but mine. please help somebody..... anybody........