HI Mate,
You have the same problem as i have with some cards.. the cards works fine and gets detected (look under about my mac) under 10.6.0-10.6.6 .. but from there and up they dont.
I have two of those cards, so i'm very open to helping you out
I'll do some testing today and get back to you.. i seem to recall some other solution was posted here on the forum.. some.. broadcom fix.. hmmm.,..