What is the exact error, and on what page?
Can't remember the exact but it was a Windows modal dialog refering to a problem with Acrobat. Clicking ok closed IE.
Haven't had that error before but have had some form of dialog popup refering to Acrobat - has happened on the main page as well as linking to the forums directly - it's as if something is spawning acrobat to launch.
Haven't had an issue this evening but, looking in my task manager, acrord32.exe is running, it wasn't before. I thought it was just something screwy with my mime type registrations but then I had the error when accessing the site today from in work, that was XP, IE7 this is Vista IE8.
Odd.
EDIT: Yep, I'm getting it when clicking on the Forum button link. If I end acrord32.exe then click on the Forum button I get the popup informing me of potential program compatibility issues with acrobat (running 7) and vista (i.e. something it spawning acrobat), clicking Run to run acrobat anyway then loads the page. If I click cancel and prevent acrobat from running then the page and IE instance just hangs.
It's okay as long as the process is running but if I end it then I get the same thing on next link.