Hi,
I've just had the exact same problem. I bought a CF Adapter and installed the stuff for it.
I can see that it mounted but it didnt work.
After a bit of Googling, I found that the Squirrel drivers cause issues on the PCMCIA slot as it's not a standard PCMCIA device.
I now have mine working fine. All I did was move the CD0: mount from the \devs\DOSdrivers draw to a place I can still access it and hey-presto, CF adapter works fine.
If I need to use the DVD drive I just go into the location I moved the CD0: mount to and double click it from there. Mounts and I can use it.
Give that a go.
Basically, anything that mounts in DOSdrivers for the squirrel (serial port too on surf squirrel) it's cause problems on the PCMCIA slot.
Hope this helps
SaGaiA