[gentoo-user] Where's my wireless AP?

[Mick]

Last night I was connected wirelessly to my access point and all worked fine. 
Well, towards the end the connection was bobbing up and down as far as my 
unreliable broadcom NIC is concerned (nothing wrong with the router).  I 
decided to shut it down and go to bed.

Today the AP is just not there!  Not there as far as this stupid broadcom 
wireless NIC is concerned.  The same machine booted into MSWindows has no 
problem seeing the AP and associating with it.  Another laptop can also see 
the AP and connect to it.

How come the broadcom cannot see it in Gentoo, but it can see all the 
neighbours APs which have a much weaker signal and even associate and get an 
IP address from one of them?!  I am lost as to what might be causing this.

Could it be some lock file that was not removed when the machine is rebooted 
or the wlan0 interface taken down?  Any ideas how I can troubleshoot this?
-- 
Regards,
Mick