Trouble with Orinoco card - Mandrake 9.1

Hi,

I'd like to know if someone has some experience working whith an Orinoco 
wlan card (Orinoco silver in my case) ? I'm trying to make it work, but 
with no success. The card is properly recognised (cardctl ident is ok) 
but badly configured for a reason I don't understand (iwconfig reports 
that it's in managed mode while I am configuring it in wireless.opts as 
Ad-hoc). When I try to force it to Ad-hoc (iwconfig eth1 mode ad-hoc), 
the OpenBrick tries to issue the command but very quickly I get a "Card 
removed while issuing command" in /var/log/messages !!!

If anyone has a clue...

Laurent