Thanks, I did achieve it as above, simply located the source solution from codeplex and downloaded. FOund the file mentioned in the linked thread for the control changed the method call as specified and recompiled. Added the new AjaxToolkit dll into my project and the fix was applied.
Not bad, though I did have to go back and download/apply to an older version of the toolkit to use as the latest version caused other issues within my project.
We are still on an older version of some controls that we use in house as well, as the new version has issues that would make it very difficult to work with our solution.