Insert Into Post issue / Custom Menu issue

After trying everything here – http://ww.wp.xz.cn/support/topic/25-imagemedia-uploader-problems?replies=1 and searching the forums and google for hours I am stumped.

I am able to upload media and the “Insert Into Post” button is displayed. The problem arises when I click “Insert Into Post.” Instead of closing the insert media pop-up and inserting the picture into the text area, the pop-up window reloads the media library.

Additionally, when I try to create a custom menu I am left with a spinning wheel and no new pages inserted into my custom menu.

I have no idea if these two issues are related, but both started today (10/22/2010). Yesterday I had no trouble with this at all.

I am running a fresh installation of 3.0.1 with no plugins and the default theme. WordPress was installed using Fantastico De Luxe on a Hostnine.com shared hosting package running PHP 5.2.14, MySQL 5.0.91-community, and apache 2.2.16.

Thought that this was a hosting issue because it is happening on my main domain and all subdomains, each of which have their own WP installation (some 3.0, some 3.0.1) but after a brief discussion with my host they were convinced that this was a WP issue.

Any help would be greatly appreciated and I would be happy to supply additional information should the need arise.

Thank you.