PowerBook - lombard freezes when inserting pcmcia-firewirecard

hi
I ve got a lombard g3 333 MHz w/ 256 megs RAM, running on X.3.9 which I havent used for like six months but which i want to reactivate now. I ve got a noname IEEE1394 pcmcia card which has always worked just fine (until very recently), I needed it for my 1st gen. ipod. Everything else (cept for the batterie) is working just fine, no problems whatsoever but when I now insert the card the whole computer just freezes immediatly. when I pull it out again, everything's back to normal and the pcmcia symbol appears in the menu (but nothing happens when I click it, obviously, as there is no card inserted anymore).
now comes the funny bit: when I reinsert it, the computer freezes again but if I dont pull it out the whole thing just shuts down or, well, turns the power off.
the computer freezes (and sometimes gets a kernelpanic) also when the card is inserted during any segment of the startup-process and it doesn't go past the grey screen w/ the dark grey apple logo when inserted before startup.
now, has anyone got an idea what might cause this strange behaviour? i'd appreciate every kind of help....