I reasently got information that the RSS feed did not work in Firefox and some other RSS readers. This is a common problem for readers who can not handle “BOM byte” the right way, (creds to Safari). The hard part for many is to find the “broken” files. Then i reccomend using a Mac or some other UNIX system and read the manuals for grep, find and xargs and execute “set nobomb” in vi or vim.
In this case it was my wp-config.php file that was broken because I quickly had edited it on a Windos computer in notepad when I rotated the password.
PS. Thanks for the report Jimmie!