I just installed the SharpForge version 0.5.14b on my system that has .NET Framework 3.5 and Visual Studio 2008 + Visual Studio SP1. That is, I have AJAX toolkit version 3.5 running and when I browse to the SharpForge web page, I am getting the following error from web.config:
I tried changing the version # for System.Web.Extensions to 184.108.40.206 everywhere it is referenced in the web.config but I am still getting this version error for other user controls in the app. I searched on the SharpForge site and all it indicated is that you would have to install AJAX 1.1 toolkit and I do not want to install the older version of AJAX along with the latest version.
I finally found few pages on the web that talk about how you can run old web sites that are built using AJAX 1.1 toolkit with the latest version with out having to install the older AJAX toolkit. You basically tell the app to use 3.5 version of System.Web.Extensions every time it needs the older version of System.Web.Extension using runtime section.
Here is a blog post that talks about it:
HOWTO: Running ASP.NET 2.0 Ajax Toolkit 1.0.x in .NET 3.5 / SP1 IIS
I spent quite a bit of time chasing this issue and I hope other people find this solution sooner.