Hoping to bump this up, and also providing some more information. The problem is still occurring -- in my client's feed (http://www.whyyoucare.com/feed), the headlines for all of the feed items are correct, but the content of the feed items is wrong. Every one of the feed items shows identical content, which is the body content of just one of the blog entries. (actually, there is a single feed item, for April 20th, where the content is correct and not a duplicate. I have no idea why that entry and not the others.)
Here's my additional info.:
I'm using WordPress 2.7.1
This is a blog that was originally at blogspot, that I imported to WordPress (about 2 weeks ago, and my client has been adding content since then).
I'm hosting at site5.
I do have permalinks settings set to "Day and Name" -- when I set them to Default and then tried to look at my feed in Safari, I got a message that there was no feed -- then I changed them back to "Day and Name" and the feed returned but with the same problem as before; I tried setting them to "Month and Name" but that did not fix the feed's problems.
I'd very much appreciate other troubleshooting advice, I've never seen this problem before and don't see a reference in any other forum postings, and it is driving me nuts!