Can't "Save Draft" or "Publish"

I am trying to create a new blog post. Every time I press the “Save Draft” button on new-post.php I am redirected to edit.php. Nothing is saved or updated. The same thing happens when I click the “Submit for Review”(Publish) button.

I have updated to WordPress 3.0.3. I have reset and unactivated all plug-ins. I have tried moving to the default theme. I have updated to Flash 10.1. I have checked config.php for any discrepancies. Does anyone know how to fix this? My last post was on November 18. Everything worked fine then.