Google reading XML as HTML

I created the feed for Google Shopping, and have tested both .xml and .txt

In reviewing the links generated, they both look like what I usually expect to see from an xml or comma delimited txt file. Google Merchant Center rejects both as being html instead of xml or txt when I try to use the fetch option.

When I simply grab the file from my server and upload the file as a manual upload to GMC, it reads everything fine. I would really rather not have to manually upload. I ran it through Codebeautify’s XML validator tool which gives this error:

Error : InvalidXml
Line : 1
Message : Invalid ‘[ “rss”, “channel”, “item”]’ found.

Suggestions on what to check to determine why GMC is reading it as html?