So I installed a fresh copy of 5.0 and everything seems to work just fine in IE7 and FireFox... but pulling it up in IE6 renders it completely useless after logging in.  I'm not sure what is causing the problem because the serverside doesn't log any errors and I'm not getting any script errors on the clientside, but all the options (menu, logout button, control panel, etc) become unclickable. 

I'm going to make a wild guess and blame it on the new version of the navigation provider because I got the same behavior with DNNBlue (I copied that skin in just to see if a different skin would work) and Extropy Minimal.  Both of those use the DNNNav provider.  I haven't tested it with a skin that uses Solpart or any alternatives but that is a next step.

Just wondering if anybody else has experienced this issue as well? 

As an aside, I've tried changing the HTML mode to XHTML Transitional and Strict as well as HTML 4.0 and all three modes have the error (my initial thought was that it was possibly and XHTML compliance issue).

Any ideas?

Well that's a nice comment and all... but not exactly helpful. 

The problem is that, as a corporate environment, there are certain standards that they (the IT team) have set for connecting and one of those is that all personnel outside of the corporate office (not to mention a large portion in the corporate office as well) are running on IE6.  To further complicate it all of those outside of the corporate office are running through Citrix which has a plethora of issues all its own but I'm more concerned about the apparent IE6 incompatibility at the time.  I have tested Opera and Safari as well just to round out my tests and all of them work well with 5.0 except IE6.

I'm going to install a different nav provider (Telerik and/or Snapsis) to the 5.0 test site and see if they change the behavior.

I've been just piddling with 5.0 this morning, I'm by far not an expert on anything.

I had 5 errors when I tried to WC3 validate. I noticed there was a thread about this earlier that got a bit heated so I'm reluctanct to put my two cents in, but all of them seem to be related to the dnnNav control. Everything seems to work great in Firefox and for the most part IE7. I hadn't thought of trying it in IE6 yet, but I did try it in IE8 beta just out of curiosity. Every thing worked in IE8 with one exception, the dnnNAV control. All it did was put the submenu off to one side or the other and made it very difficult to navigate.

Couple of things I've noticed and changed. App_Browser folder vs App_Browsers and moved the contents over.

Also had an issue with the fckhtmleditorprovider.dll that couldn't be found. I simple moved the dll to the bin folder.

 Edit: one more little odd behavior. When I use the dnnSearch in IE7 it seems to skew the containers on the page a bit. Makes it hang off the skin to the right about 50 or so pixels? don't know how else to explain it.