I'm having big trouble with a PCMCIA on an IBM Thinkpad. Actually it's two problems with the same card. The card is a Sierra Wireless AirCard 850. The trouble started at installing it. At first we tried to install it on a brand new IMB ThinkPad t43. We installed the software first, and put the card into the PCMCIA slot afterwards, as described in the manual. The computer (running Windows XP Pro SP2) couldn't figure out what kind of card it was, and only asked for the PCMCIA MTD-0002 driver. Which it of course couldn't find. There was no help in trying to install the driver manually. I've tried to update every driver and other software patches and upgrade from IBM, including upgrading BIOS. Every Windows patch is installed. I've tried to uninstall and reinstall the card and software. I get the same reaction whether I boot the laptop with the card or insert it afterwards. I've tried to install it on another computer (thinkpad r51), and still the same problem. The next day I inserted the card on the R51, and suddenly it could find the right driver. But I couldn't enjoy it for long, as it started to make my computer freeze totally, and no ctrl-alt-del was of any help. Ejecting the card unfreezed the computer at once. Today, the same computer asked for the MTD-0002 again, but found the right driver after reboot. It made my computer freeze several times, but at last it seemed to quiet down. As far as I can see, there's no IRQ conflicts, but I've only had the chance to check that out while the card was actually working. Googling didn't give any help on this matter, only that some people have experienced simular problems with other PCMCIA cards and other laptops, mostly Compaq.