Oh darn I left out, after security info

Therefore I would definanly upgrade (by the way I did a lot of research recenly on this issue and as far as security goes, DNN seems to be better and more secure than most of the Content Managers out there.  The main "holes" seem to be install issures and user. (granting write permissions when not needed on certain folder, not changing the password to the admin and host account or deleting them as the book recommends etc.

If you have a version earlier than 4.4 and speed is an issue, I can tell you that I noticed a real performance gain in 4.4 as promised, why , I dont know, it just did   Therefore I would definanly upgrade, without a doubt.

The best list is (as always) the changelog @ http://support.dotnetnuke.com/project/ChangeLog.aspx?PROJID=2 . If you need some detail on any issue click on it and you can view it's release notes. At some point in the future we will probably extract this into a file that's distributed with the release as some people prefer that format (personally i prefer the online version as you can see the full history and cross-referenced issues).

Core security issues will always be always have bulletins created on the security page @ http://www.dotnetnuke.com/Community/SecurityPolicy/tabid/940/Default.aspx , and will always be blogged about on the security blog feed @ http://www.dotnetnuke.com/Community/Blogs/tabid/825/BlogID/28/ParentBlogID/5/Default.aspx which I recommend people subscribe to

Cathal