On IE8, when editing a long article, the text being entered will jump/scroll to the bottom of the textarea as you type. This is very annoying for editors who choose to use IE (yes, there are some), who have to, or who just don't know any better (they both deserve our pity).
The issue appears to be the handing of the editing textarea when its width is set to 100%. This appears to have previously been "fixed" by reducing the width to 96% for IE. IE8 does not change the situation but does prevent this fix from working - unless it is in its "IE7 compatibility mode".
If a website is on this list, it will automatically have IE7 compatibility mode applied:
res://iecompat.dll/iecompatdata.xml (accessible only from within IE8)
This includes all subdomains of wikimedia.org, wikipedia.de, wikipedia.org and wiktionary.org, but not all Wikimedia sites, and obviously not *most* third-party users (wikia.com and wikihow.com got lucky).
If the default cannot be fixed to work in IE8 and everything else, a "solution" might be to add one of:
The HTTP header: 'X-UA-Compatible: IE=EmulateIE7'
The meta tag: '<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7" />'
This would force IE7 compatibility mode as described in http://blogs.msdn.com/ie/archive/2008/06/10/introducing-ie-emulateie7.aspx
It should also be possible to detect IE8 by searching the User-Agent for 'Trident/4.0' and only sending the header or meta tag then. User agents - along with other details of compatibility mode - are given at http://blogs.msdn.com/ie/archive/2008/08/27/introducing-compatibility-view.aspx
OS: Windows Vista