I am seriously confused with this issue. I've set up some pages to ban, unban and approve a user. On localhost, it works fine. I can ban them and their record is updated to show that. I can unban them and again, it's updated. I can also approve and all is fine.
However, when I uploaded this to a website I'm having a big problem. When I try and approve a user, or unban them - it changes their banned/approved state and then logs me in as them! And when I try and ban them, it just logs me out.
Here is the code I have (I'll show you the banned pages, as they're all basically the same):
Not this this will fix your issue, but you should definately consider using a document type declaration just above the <html> opening tag. Without it, you are surely going to run into quirky issues since IE will go into quirks mode without a proper doctype.
Just start getting use to HTML5... it will require you to stop using some of the deprecated tags you have listed above, but it doesnt require you to use HTML5 elements.
sorry for a response that isnt related to the question, but again...you will come accross cross-browser compatibility issues eventually if you havent already.