Prism 2 scanning

I've been trying to implement scanning on my PowerBook with Prism 2 
card (Firmware 9-1.4) and I'm getting results which don't seem to agree 
with your original  message on the subject.

Specifically, sending the scan-request RID appears to do nothing.  I 
can request scan results whether or not I send the RID, and the 
behavior is as follows

1) If the card has no desired network id set, I get all APs  and ad-hoc 
machines(usually, anyway)
2) If the card is associated with a network, I get only the associated 
AP
3) If the card is has a desired network set but it isn't associated, I 
sometimes get all APs.

The scan reason is always 3, regardless of whether I ever sent a scan 
request rid.

Can you provide additional clarification?  Thanks.