I set the RSS feed on my blog http://words.mikefinley.co.uk to be cached by W3 total cache, as that was the recommended setting.
I tried to submit the RSS feed on my site to bloggrader, and it complains that the feed isn't valid. I also tried with bloglines (which is the newsreader I usually use) and it doesn't see anything in the feed.
If I disable caching of the feeds, both are happy with the feed. Its currently left that way, though I can easily switch it back to cached if you want to test - at present its unlikely anyone but me is actually using the feed.
Using WordPress version 3.0 and W3TC version 0.8.5.2