automatically connects to non-preferred network

[Ben W <benwilber gmail com>]

I am running Ubuntu Edgy with NetworkManager 0.6.3 on a macbook with an 
Atheros wireless chipset using ath_pci driver.  In my apartment there 
are many wireless access points.  When I first set up my machine I had 
trouble connecting to my access point with WPA2 encryption so I tried to 
connect to a network nearby which had no encryption which worked fine.  
I have since solved the connection problem, however, when I boot my 
machine NM automatically connects to that non-preferred network.  Am I 
able to remove that as an accepted network?  Is there a config file 
somewhere?  I can't seem to find it.

Any help would be great!

Ben