I have been battling a problem of 404 errors on comments for 30+ days. The comments do record and post but users get a 404 error when commenting and is very frustrating. I have deactivated all plugins, no luck, switched to default theme and no luck. Permalink is set to /%postname%/ I have checked everywhere for a trailing space with no luck so finally tonight I changed permalink structure to /%category%/%postname%/ and made a comment and it worked fine but when switched back to /%postname%/ the 404 error shows again. Any suggestions on how to resolve? URL is http://www.learntocatchcatfish.com/catfishing-month-in-review-may-2010/comment-page-1/#comment-1044