Richard sent me a screen grab so I see that, indeed, there is a problem in IE. I will investigate possible solutions. That said, Internet Explorer is really the problem, as it is notoriously unfriendly to things people other than Microsoft have standardized for the Web. There's an article
here which is kind of dumb, but skip down to the bullet points for the main reasons why using IE is a bad idea. I recommend downloading and using a free replacement browser such as Firefox or Chrome for a number of reasons.
All that said... I'll see if there's a way to make IE behave with PhpBB. So our fixit list so far is:
1) Make IE stop aligning text with bottom of avatar image
2) Restore a way to jump to
first unread post in a thread
3) Visually differentiate threads better like open/closed folders used to
4) Make links force a new window
Anything else (that was practical, as opposed to "Go Back" which isn't?)