Permalinks STILL not working!!!!!

I just upgraded to WordPress 2.5.1 on my Yahoo! hosted blog and the only Permalinks setting that works is the Default option. With other options, I get the error 404 page. I’ve gone through the support forums and tried all previous suggestions, from making sure that the correct code was in my rewrite.php file to adding “index.php?” into the permalink chain, and none of it works. I’ve deactivated all the plugins and nothing works. Yahoo! has this plugin called “Customizable Permalinks”, but when I activate that and try to set any option other than the default, my site seems to get caught in an endless loop when trying to find my post.

I was previously using 2.0.2 and “Day and Time” worked fine. That’s how Google tracks my pages/posts so I really need to keep it that way. PLEASE HELP!