RSS Parsing Issue for Specific Feed?

[Lurick73]

I've been spinning around on this issue for a while now and decided to throw in the towel and ask for help. I'm using the Enigma RSS readers 1 through 3 and I can get any other feed to work except this one:
http://rss.slashdot.org/Slashdot/slashdotMain
No matter what I try it always comes back saying that it's an invalid feed or (on older 2.7 version of Enigma) Rainmeter logs show a RegEx parse error of -1 which isn't exactly helpful either.
Any RSS validator I put the link into comes back that it's valid and I've tried the RSS 0.9 version as well as the Atom link:
http://rss.slashdot.org/Slashdot/slashdotMain/to
http://rss.slashdot.org/Slashdot/slashdotMainatom

"Could not identify a valid feed format" is the current message on the latest version of Enigma.