Proper feeds

By default, Blogger sorts items in its original feeds by their date, not by their date. They do this so that if you update a really old post, it jumps right back to the top of your feed so subscribers can see what you've changed. However, there are publishers who have contacted us stating that they really don't like this behavior and wondered if FeedBurner could re-sort items in their feed. Fortunately, no service is needed from us; just a small adjustment to your FeedBurner feed's "Original Feed" address is needed to make sure Blogger always sorts your items by date alone.

To make this change, sign into your account, click on your feed's title, and then click the "Edit Feed Details..." link near the top of the feed management page for your feed. In the "Original Feed" field that appears, change the address from something like:

http://orkuttricks.blogspot.com/feeds/posts/default

to

http://orkuttricks.blogspot.com/feeds/posts/default?orderby=published

Then click [Save Feed Details]. FeedBurner will immediately rescan the original feed, which should now be sorted by published date alone. Your FeedBurner feed will faithfully reflect the changes you made under the hood to the Blogger source feed. Good times!

from feedburner forum