Ad hoc WEP connection

[Patton Echols <p echols comcast net>]

I thought I saw this answered somewhere not too long ago, but can't find 
it in the list archives and can't seem to construct a rational 
googleism.  So any thoughts:

I am running network manager on my laptop, it manages WPA at both home 
and office, and also successfully connects to open access points, no 
problem.  Today, I was at a coffee shop that has free WIFI, but you have 
to get the day's WEP key from the counter.  I guess they want to slow 
down the drive-by surfers . . . whatever.

I pointed network manager at the AP, it asked for the WEP pass-phrase, 
which I gave, no "connection".  The network monitor icons seemed to show 
signal being exchanged, and showed signal strength, but the no actual 
communication was going on.  Am I missing something?  Do I have to 
configure WPA-Supplicant for each WEP I want to access too? 

Thanks for any pointers.

Network Manager 0.6.3
Ubuntu Edgy
aetheros card - madwifi driver

Patton