XML Error associated with mscoree.dll

A solution I have created consists of a .dll to interface with ESRI's
ArcMap application as well as two executables, an XML document
(AddPLSS.xml) and an install package. It compiles and installs without
any problems, but when I try to open ArcMap, I get the following error:

XML Error: The system cannot locate the resource specified. In
(failed) mscoree.dll/AddPLSS.xml.

The XML file itself seems to be included in the .dll and the install
package. It ends up in the right place on the client machine. In
fact, this application was working well until fairly recently. I did
add one of the executables to the solution, but I never changed
anything related to the XML file.

I cannot find any reference to this specific error anywhere via Google
or MSDN. Hopefully somebody somewhere has seen this sort of thing
before.

Thanks,

David Snyder
Resource Data, Inc.
Anchorage, Alaska

The XML really wasn't being located as it turned out, which was
somewhat implied by the error, but in a completely unintelligible
manner. Oddly, prior to fixing the root cause of the error, I was able
to get rid of the error message by completely cleaning out all entries
related to my application in the registry. Not a recommended thing to
do, but I was able to debug it properly after getting rid of the error
message.

David