Official word from Microsoft Engineer, quoted from email:
"I have contacted the development team in this regard.
I am informed that there won’t be an Update Rollup 22 for V4. The volume of bugs for that version have dried up, so at the moment so they are not planning any more updates for CRM 4.0.
CRM 4.0 is not supported on windows 8 and IE 10.
IE 10 is being considered for CRM 4.0; it would be a while before anything is released for the general public."