[Angel-Wings]

Hmmm - after doing the 2.1 upgrade there's a strange problem.

Entire Chatbox stays empty for IE users - Opera & FF work fine. The archives work and all chats are shown, still IE users have an empty Chatbox.

There're no JS errors, mod_sec reports nothing as well and the Webserver / PHP logs reports nothing as well.

EDIT: Problem solved

Problem was that is was set to retrieve the YUI components NOT from the site itself. So Users of a better IE configuration using the Zone Settings to whitelist sites, setting their security settings to "High" for the default Internet Zone will have a problem with external JS code.
The same applies to Noscript Users of Firefox who whitelist the Board URL.

Yup - that's it. No mod_sec / suhosin problems.

Related to mod_sec & VB - like mentioned in this thread to disable it - do NOT do it. Instead, run it in Detection Mode whitelisting files as required.