I'm not sure if this applies to all versions or just to IE 10, but whenever I try hitting enter to add a line break it does nothing in IE 10 (the desktop version on Windows 8 Pro x64, not using "compatibility mode"). It's as though I pressed a dead key. Pressing enter works just fine in Firefox on the same machine so it seems to be browser-specific.
I'm using Firefox for this post (hence this new paragraph), but for various reasons typically use IE for most web browsing, I have no interest in a browser flame war or in a discussion of the relative merits of the different browsers. Just wanted to report a bug that I'm experiencing. Thanks!
The only other forums I regularly use are the forums at http://xboxforums.create.msdn.com/ and they do not suffer from this issue. Also, if I switch IE to compatibility mode then I can use the enter key in IE here. But that messes up some other alignments. I dug further and noticed that the http://public.gamedev.net/public/js/3rd_party/ckeditor/ckeditor.js file is doing version checking (rather than feature checking) and doesn't have a check for IE 10 so its possible that that is the problem (or partially it, or related to being it).
The enter key is also completely broken in Opera but everything works fine in every other forum I go to =/ It seems correct at first, but randomly it will decide that newlines can only be added at the beginning of the post instead of where the cursor is (usually after undoing, though when it triggers seems to be at random). Something similar happens with pasting, it adds only at the beginning in such a situation. Moreover, try to go into "More Reply Options" and all the blank lines get collapsed... even though they're still there and will show up if you post. It's a complete mess and horribly unpredictable whether it's going to work or not.
Don't pay much attention to "the hedgehog" in my nick, it's just because "Sik" was already taken =/ By the way, Sik is pronounced like seek, not like sick.