Following this post
by .NET Musings I could publish my TFS Installation to the WAN so I
could access it from out of  the office. Almost everything went OK
but there’s an issue left to solve.

Issue:
When you access from the WAN to a WSS site created by a TFS project, the WebParts that access the
Report Server are not trying to contact the Report Server at
http://tfsreports.domain.com/reports, instead, them try to find the server at it’s LAN private URL (http://DTServername).

Symptoms:

When you access from the LAN (Private Network), the WebParts finds the ReportServer and everything is OK.

When you access from the WAN (Internet), the WebParts show an “Action Canceled” error page.

Solution
It’s clear that the solution consists in telling the WebPart that URL to access de Data Tier Server is http://tfsreports.domain.com/reports and not http://DTServername. The WebPart ASP.NET page ( tfsredirect.aspx ) gets this URL from the following Windows Registry Key:
HKEY_LOCAL_MACHINE \ Software \ Microsoft \ VisualStudio \ 8.0 \ TeamFoundation \ ReportServer \ Key
Just change that key value to: http://tfsreports.domain.com/reports and you are done!

In addition to .NET Musings post, I would like to add a clean version
of the XML Configuration file used with the TFSReg.exe command. You can get it from Here

I hope this helps!