Randomly, the 'Mark site read' box is almost opaque (with broken text) and you can't click on it as it takes you to whatever link is lying beneath it on the bar across the top of the page. You have to refresh the entire page to get rid of the useless box and you cannot do anything else while the drop down box is open.
The same thing occurs randomly with the 'Sign in anonymously' check box. The fields to enter name and password are fine but the anonymous log in box is broken up and opaque and you can't click on it at all.
Also, periodically, the site logs you out of anonymous posting (when you can actually click on the box) and you're visible again even though you haven't touched or changed anything.