Afraid I can't work out how to use that reporting site, so I'll have to add my finds here:
Browsers: Firefox (latest) and IE 7
Logging inI don't get any confirmation when I log in, and it stays on the login page instead of sending me to the control panel.
Uploading an image: Browse Button
On the image upload page the 'browse' button is all odd.
Uploading an image: Uploading
A bit of a usability issue this one. After selecting the image to upload, it isn't obvious you have to press 'upload' to get it going. I ended up spending a couple of minutes waiting for the progress bar to fill up.
IE7: When I click upload I'm sent to the 404 page.
Creating an ArticleWhen I click 'add article', I get sent to this page:

Writing an articleThis appears at the bottom of the editable columns:

Deleting an ArticleI get the 404 page when I click the 'delete' link next to an article's entry in my document list.
Editing an Article
I get a fatal error when I try to edit an article
Character Bio: IE7When I go to the character bio page in IE7, I get this:

Works fine in Firefox
Character Bio: Uploading an imageThe upload button is deactivated, and no browse button is present.
Help SectionI get this page again:

That's all so far, I'll keep clicking for more breakages!