If you have compression turned make sure you add the following entry to your Compression.config in the excluded paths section.

<path>WebResource.axd</path>

I have successfully used Ajax RTM 1.0 with DNN 4.4.1. However, I was not able to do this at the page or container level so far. I was hoping to make an Ajax Update Panel container but am having problems getting it to work. I was able to create a new module and drop a script manager, update panel and password strength extender on to it. It works like a charm.

To do this I installed the RTM 1.0 release, and copied the ajax settings in web.config to the dnn web.config. I checked compression.config and WebResource.axd was already excluded in my config. Then a dropped the AjaxControlToolKit.dll into the bin folder.

If anyone needs more detailed instructions I will be glad to post them. A quick tip is to create a new Ajax site and copy the settings from that config to the dnn config.

You get 1 cool point from me. I've been fighting for two days. Changed web.config 10 different ways, moved DLLs, chagned code, uninstalled/reinstalled AJAX 1.0 etc........

Changing to <xhtmlConformance mode="Transitional"/> did the trick!!!!