If you're using the orinoco_cs drivers then yes, you need to patch your drivers. Info here:

http://airsnort.shmoo.com/orinocoinfo.html

Basically, you'll be recompiling your kernel with PCMCIA support turned off. You'll then download pcmcia_cs as source, patch with approrpiate airsnort patchfile, compile and install.

That said, I found that compiling it was a fuss and I had to reconfigurure my kernel's config file before it would actually compile correctly. I've finally gotten the patched drivers running okay under Debian Woody, and iwconfig now shows monitor mode as an option for my Speedstream SS1021 card, but how to actually activate it, and get Airsnort to do anything besides give me a "Unable to enter monitor mode" message, is still something of a mystery to me. If using Kernel 2.6, beware that none of the drivers in the pcmcia_cs package are 2.6 compatible, though the other non-driver items are fine.

At this point, I think I'm ready to just buy some other WiFi card which doesn't need patched drivers to Airsnort.

Jeff