^^ Weird yes. I tried IE8 and that works fine. I will try some different things to see what works.
Is it showing that you are logged in when you come back? Also, when you come back to the site, try clicking on the Forums link, in the upper left (sorta like a refresh) and see if it stays the same skin or no.
When I first have stuff installed, if I would leave the site, and then come back, it would show that I wasn't logged in, but if I clicked on the forums link, then it would show me logged in and if I had a different skin, that would load as well. The problem went away for me, and I tried to replicate it on another computer, and I couldn't.
Let me know what you find out Dan.