SMP and ath Wifi driver - fatal trap 12: page fault

Hello current's,

    I have the ath driver running for a DWL-AG520 on FreeBSD 5.2.1, the card
seems fine for a short period of time, but then as data starts flowing the
machine hangs with a fatal trap 12.
The machine is a Dual Processor PIII on an Intel BX Chipset with 700MB RAM.

I think this may be SMP related as I found this whilst googling -
http://www.houseofcraig.net/README-0.2.0pre7.txt
Which mentions trouble with that card and SMP.

My Question is - is the problem SMP when using ath and if so how do I fix
this?? If not what the hell is it?

The exact error is:

fatal trap 12: page fault while in kernel mode
    cpuid = 0; apic id = 00
    fault virtual address = 0x34002d85
    fault code = supervisor read, page not present
    instruction pointer = 0x8:0xc06b509e
    frame pointer = 0x10:0xde006a8c
    stack pointer = 0x10:0xde006a5c
    code segment = base 0x0, limit 0xfffff, type 0x1b, DPL 0, pres 1, def32
1, gran 1
    processor eflags = interrupt enabled, resume IOPL=0
    current process = 36 (swi1:net)
    trap number = 12
    cpuid = 0
    boot() called on cpu#0