How many SSIDs can be listed?

[Robert Moskowitz <rgm htt-consult com>]

Ver 0.6.4  in Centos 5.1

I am seeing 17 SSIDs in the current list.  But I am not seeing one that 
I expected to see.  And some of the listed SSIDs are 'stale'; that is 
they were visible in the part of the hotel I was in a couple minutes 
ago, but not in this part.  So I guess a second question is how do you 
force a scan to produce a current SSID list?

Perhaps the question may be how many APs can be handled and then those 
are turned into the SSID list (when more than one AP per SSID is found 
as in the case of some of these SSIDs).