asterisk users - Apr 2005 - Extension busy issue on TDM01A

All,

I've very new to * and am trying to get it up and running.  I have * running
on FC3 with a TDM01A connected to my POTS line.

Asterisk loads without issue and my X-Lite phone logs in without issue.  I can
dial other extensions fine.  When I try to dial an outside line (with 9 first) I
get a "All circuits are busy".

ztcfg -v shows "1 Channel configured"

On the asterisk console, the failure happens after:

Executing Dial("SIP/201-0275", "ZAP/g0/6047030223") in new
stack
  == Everyone is busy/congested at this time

I only have 1 FXO port open, but #4 is lit up green on the back.

What can I do to troubleshoot this further?  Is there a way to test my TDM01A to
ensure it's working?

If there is a wiki reference I should be reading, let me know.  I'm a little
light on PBX terminology.

Thanks for any help!

-- Aaron