Reassocation problem

I have a Sharp SL-C3100 with a linksys WCF12 802.11b card.

I have 3 access points it needs to talk to; two are in my house, and one
is in the van.

As the Sharp is very portable, it was my hope that it would
automagically reassociate with the nearest AP for best signal strength.
Failing that, I was hoping it would at least reassociate when it
lost one AP and was in range with the next.

Unfortunately, either the card or the hostap drivers are very stubborn,
and once the Sharp associates with an AP it will not change, even if
that AP goes down and it is in range of other APs.

Is there anything I can do to make it a floater? I need for it to
reassociate automatically, and AFAIK, this is something that should just
happen. IN my case, it doesn't.

My worst test case is pulling the power on the AP it is connected to;
the sharp keeps trying to find the AP, but even if I turn the AP back
on, the Sharp will not reconnect....

Is there some magic I have to do with the hostap drivers to make this
happen?

Thanks,

--Yan