newbie: getting wireless going on hardy

[Jeffrey Berger]

Installed from the network cd in what I thought was the completely  
standard way.

When I try to use Network Manager to set up my wireless card, I run  
into immediate problems getting going.

Clicking "Unlock" on the Network Settings window produces the  
authentication screen. However, a few seconds later, an error box  
appears with the message "Could not authenticate. An unexpected error  
has occurred." The error box occurs whether or not I type anything at  
all into the password field.

There's no other OS installed on the Inspiron 7500 I'm using.

Suggestions?

TIA
-JB