Most of the major browser vendors released a significant new browser version within the span of month.  Some of those browsers, like Chrome and FireFox, didn’t introduce any significant new issues that impacted DotNetNuke.  Internet Explorer on the other hand is causing some problems.

So much so, Microsoft has released documentation on how to force IE 9 compatibility mode to IE 7. "Document compatibility defines how Windows Internet Explorer renders your webpages. This article explains document compatibility, how to specify the document compatibility mode for your webpages, and how to determine the document mode of a webpage."

Microsoft has always had issues with compatibility, adhering to standards ans just plain being buggy. IE 9 has made some improvements, but it falls short and there a plenty of areas for improvement. Granted some of the issues in IE 9 are the by-product of developers always having to compensate for issues in older IE versions that may not be present in IE 9.

DotNetNuke (DNN) responded by releasing a Telerik  "patch" for DNN versions newer than 5.5.x  including the latest version 5.6.2. Patch might not be the right word here, it really a newer Telerik assemblies that will be included in the forth-coming DNN 6.0.

There's a reason I choose FireFox as my daily browser, it just works, and works well on ALL webpages (government sites aside, that's a topic for another time.)