I have found some issues with the forum when using Internet Explorer 9...
Drop down menu does not work properly
If I click on my name, the menu flashes up and then I am taken to my profile page.
If I switch to compatibility mode, the drop down menu works, but there are some formatting anomalies. Some of the text gets displayed on top of the forum menu bar (eg the avatar picture and quoted text, etc
I hope this information is useful.