This is a pretty common problem and has nothing to do with e-smith as I have them running on a number of sites hosted on an e-smith box. I will suggest a few things:
1. Be Patient and set the refresh time at 1/2 hour in the rss newsfeed block configuration as they do not (in my experience) just pop right up and get to work doing what they are supposed to be doing.
2. make sure that the rss block you are using is the 'rss newsfeed' and not 'rss extra' as I have never had any luck with getting that to work.
3. Make sure the link you are using is actually valid. Some of the default newsfeed links do not work (something we need to remedy by the next release).
4. Make sure that you understand that the rss newsfeed block does not accept the newest rss protocall. I have not run into this except for the phpwiki module recent changes feed, but we have a fix for that that should be out shortly.
For the most part I always reccomend that you fix a nice strong drink and let the block do it's thing for a while. One of these days someone will update the code and we will all be happy news junkies.
If you have more trouble please join us on irc.postnuke.com #postnuke-support or via the java irc module on
http://postnuke.com.
Best regards,
Steve MacGregor
PostNuke Documentation
http://docs.postnuke.com