Reading P2 cards via Expresscard slot - adapter hassle!

Hope someone can help with this... (I may post in a couple of other forums, as I'm not sure whether it's better to ask Mackook Pro crowd or an FCP crowd)

I want to read Panasonic P2 cards on an old Macbook Pro (Macbook Pro 3,1, Intel Core Duo, running 10.6.8).

To take care of the physical interface I have just acquired a PCMCIA to Expresscard adapter, specifically this model:

http://www.ebay.co.uk/itm/221612762683?_trksid=p2057872.m2749.l2649&ssPageName=S TRK%3AMEBIDX%3AIT

(The card is sold as being OS X compatible, and not requiring any additional drivers)

And I have installed the appropriate Panasonic P2 drivers.

But the card doesn't mount on the desktop when I plug it in.

I think there may be some communication between computer and card, as the greyed-out item in this pull-down Finder menu changes when it is plugged in.

Any ideas folks?

(BTW I use a newer MBP for editing, but as it doesn't have an Expresscard slot I can't use it to import from P2. I know there are USB card readers, but they're on the expensive side and I'm after a cheaper solution)