Internet Card Hangs My Computer For No Apparent Reason, Any Advice?

Hi people. Got another PC issue on my laps now. My friend subscribes to Starcomms Internet using the EVDO card in his PCMCIA slot on his laptop PC. He subscribed to the service since November and it has worked ok. His laptop is a Dell Inspiron running Win XP Home. He asked me to take a look at it when he noticed last week that the PC would just freeze whenever he inserts the card, if he removes it goes back to its normal working condition, but if he inserts it a second time, it freezes completely and needs to be restarted (for sure).

Now I/we've tried several things. Running a system restore, uninstalling and re-installing the PC Card Modem, tweaking modem settings etc. At a point we decide to disable the default modem which we suspected could be contending for the same resources as the card. Then we inserted the card into the slot and it didnt freeze! We adjusted the modem settings (could only be done when the card was recognised and the PC functioning) and while were reducing the modem speed (bps) it froze again. Despite this the card works well on my own laptop.

Ok it was mind boggling but we decide to backup the data and reinstall the OS (abi?). Now we install Win XP Pro creating new partitions and formatting, and it installed fine, but the PC still froze when the PC Card was inserted! And the card still works well on my own laptop.

What could be the cause of this? and what could be the solution?

Your advice shall be appreciated, thanks!