It occurred to me that Jeff_W wrote in gmane.os.netbsd.help:
> Martijn van Buul <martijnb@atlas.ipv6.stack.nl> wrote:
>
>> It occurred to me that Jeff_W wrote in gmane.os.netbsd.help:
>> > Realtek, Rtl8139, M^?M^? (manufacturer 0x0, product 0x0) Realtek Semiconductor 8180 802.11b (ethernet network, revision 0x20) at cardbus0 dev 0 function 0 not configured
>>
>> Hm, next time, I should pay more attention. It looks like this isn't a rtl8139
>> at all, but an rtl8180 which is being misidentified. the rtl8180 is supported
>> by the rtw driver. 
>
> Okay, so then why isn't rtw picking it up?  Is it only seeing the "Rtl8183" ?

I dunno. There's something going wrong while configuring that cardbus card.
The "manufacturer 0x0, product 0x0" is suspicious. It's just a hunch, but
take a look at man 4 cardbus - especially the last paragraph.

Are other cardbus cards known to be working, or is cardbus dead altogether?

> Is it worth bothering with or should I just chuck it?

I don't know :) Personally, I'm a bit weary about realtek stuff. But I 
wouldn't be overly surprised if this turns out to be an issue with the
laptop, and not with the card.