I am also having this same problem however there is no .htaccess file. I have confirmed this at the consol level (using “ls -la”) I do have one in the root of my wordpress install that tells everything to use php5 (this webserver has php4 and 5 installed) it also contains some mod rewrite rules. I have no visual editor and the box is checked in my profile to use the visual editor.
I experenced this after upgrading to 2.3 is there a solution or do I need to think about reverting to 2.2?