airPanel v150p - can't connect to Windows XP Service Pack 2

[BPieslak]

My hard-drive recently died on me, and I had to re-build my computer from
scratch. Now that I'm back up and working, I can't get my ViewSonic airPanel
V150p to connect.

I previously connected my V150p *before* installing XP Service Pack 2. And
after installing SP2, it still worked.

Now that I've re-built my computer, I've installed XP SP2 *before*
connecting my V150p, and now it won't connect

I have opened up all of the RDP ports in the windows firewall.
I have even tried disabling the windows firewall completely.
My V150p still can't connect to my XP box.
I *have* been able to RDP into my XP box from my work laptop, so I know that
RDP is available correctly through the windows firewall.

Running the SmartDisplay connection troubleshooter, it fails on step 3,
giving me the following message:

==begin==
"Problem Found
Reconfigure firewall

Your computer can contact your Smart Display, but your Smart Display cannot
contact your computer. A firewall may be preventing your Smart Display from
contacting your computer. To resolve the problem, you may need to reconfigure
your firewall to allow Remote Desktop Protocol (RDP) connections.

Tell me more about Remote Desktop Protocol

After you have configured your firewall, click Next. "
==end==

I'm not sure what else to do, and I could really use some help.
Hopefully I do not have to re-install Windows XP again.

Thanks to anyone who can help me!
-Brian