tag feed creates feed and doesn't pick any posts in feed

I setup Post Indexer and it appears to be working. I loaded the tag-feed.php to the domains wp-content folder.

The tried to address a feed for a specific category

http://www.fmsreliability.com/wp-content/tag-feed.php?tag=musings

and

feed://www.fmsreliability.com/wp-content/tag-feed.php?tag=musings

is what shows up in Socialite (default RSS reader) and it then doesn't populate with the post from musings (under fmsreliability.com/education/musings

I was able to set up a feed directly with

http://www.fmsreliability.com/education/category/musings/feed/

and it immediately populated with the one post in musings.

Am I missing something with the feed address? or is something else not working?

cheers,

Fred