Thnks to crptodan, quietman7 & noknojon sugggestions, I have google search for a IT description and solution to my issue of Win Updates and MSE security not updating; see the infoworld link below.
Apparently Microsoft have a known bug in the Windows update Agent 'wuauclt.exe'; which was triggered by the November updates.
The complete solution to my problem was found in Jiver's comment in infoworld's discussion, where he gives the MS forum link:
I followed Xircal's 'Most Helpful Reply' precisely - finishing with his manual IE8 November update download - with the result that MSE & MS Update are now updating normally.
I found MSE & Malware Pro seem an effective combo without loading my elderly XP PC too much.