Serving XML

A site I regularly work on has, in its web root, a static XML file. This
XML happens to be an ADO persisted recordset with 0 rows, all of ~3 KB in
size. (Clients can open it, insert records, and then push the appended
recordset back to the server for an UpdateBatch, but that's not important to
this question.)

Everything works, however, during an analysis of the site's IIS logs, I
noticed that requests for this static XML have, on occasion, taken as long
26 seconds to be processed! The thing that's mind-numbing is that we have
an ASP script that gets requested 2-3 times more often, that, when called
with a certain parameter (that causes it to return last error details stored
in the session) has never taken more than a sub-second to process, no matter
how busy the server is!

This has led me to wonder if this XML is truly as static as I'd assume, so
my question is, does an xmlns attribute cause an implicit request, thus
imposing a dependency on a foreign site? Specifically, does
"xmlns:rs='urn:schemas-microsoft-com:rowset'" cause an http request to
schemas.microsoft.com? Code: