RSS feed – Format missing – Big problem!

Hello all,

First time posting. I have searched for three days on this problem and I cannot find a solution. I see it is not an uncommon issue and I hope some can help.

For the last few posts of my blog (jonvaldivia.com) my RSS feed (jonvaldivia.com/feed) throws a non formatted text and no thumbnails. My visits are dropping as most people read my entries through feedburner email subscription or feed.ly, and this problem makes my content very unpleasent to read.

This is what I have tried:

– Disable all plugins
– Change themes

None of this seems to work, although I am unsure if the RSS feed need to be rebuilt after changing themes or disabling plugins to see the effect of these changes.

I saw this happened on old versions with a plugin called podpress. I do not have that plugin installed, although I have a podcasting plugin. I have tried to uninstall it and the problem remains.

I cannot keep updating my blog until this is solved.

I really appreciate your help on this one.

Jon