Since upgrading to 2.8 (Theme is 333) my feed has gone awry in some browsers (IE).
Posted on wp forums and no help.
So, tried feedburner which works ok on the subscribe by email function.
So, thought try with feedsmith but the plugin gives "The plugin does not have a valid header." when try to activate.
Therefore I have two probs
First the feed itself. If cannot sort that then feedsmith may be the answer but second prob is how to activate feedsmith?
Url for feed is http://www.luxuryrealestate.co.uk/feed/
Tried removing images but still problem.
Changing code from utf-8 cured the problem but gave another one as then the euro symbol was not showing correctly.
Any help much appreciated.

There have been a few lengthy threads about RSS and Feedsmith. I noticed that you're missing the line
xmlns:slash="http://purl.org/rss/1.0/modules/slash/"

in your feed but I couldn't find more than that. Please search the forum for those Feedsmith threads

Hi Flynn,
the line is in the source
"
xmlns:atom="http://www.w3.org/2005/Atom"
xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
xmlns:slash="http://purl.org/rss/1.0/modules/slash/"
>

<channel>
"
Feedsmith is not the problem, just a way around the problem, if I could activate it.
Cannot see on a search anyone having the same problem activating re "The plugin does not have a valid header."
I would prefer to try and find out why the normal feed is now not working.

Not an ideal solution, would prefer just using normal /feed/ in wp, but downloaded fdfeedburner and now feed is redirecting to feedburner.

It might be a blank line at the bottom of Atahualpa's functions.php or WP's wp-config.php

Could even be hosting related settings

I am having this same exact problem(s).
My site is www.thejobswami.com hosted by BlueHost.
1. FeedSmith says Header is invalid
2. I cannot get the yellow RSS Box when I set up the RSS Feed? It just shows a post but not where to subscribe to an RSS Feed.

Thanks.

Bill Morgan

i only pull 10-20 feeds to my frontpage. tried feedsmith once, without much success.

instead, i use 'rss short code' plug-in and
-feedity
-feedburner
-rss feed from individual site

hth,
-g