Perhaps you could ask a friend with a laptop to try out the right-angle adapter for you?
As someone else suggested, you could try using a regular PCMCIA 16bit network card or a modem, just to see if it works in the right-angle adapter...or even a PCMCIA 16bit memory card.
It could be that the adapter itself causes some sort of interfearance with this particular PCMCIA WLAN card.
Can anyone confirm that they successfully used this or any other PCMCIA WLAN card with A1200 and a right-angle adapter?