I know you don’t care for M$ however before starting a rumor about an infection,
it might be wiser to eliminate everything else.
I have no problems getting to the update site from my XP system. Since there’s nothing for me to download,
I can only confirm that getting the update information or lack thereof isn’t any problem.
I fully agree with you, better do a full scan with MBAM and SAS or give us a hijackthis logfile as attached txt to analyze. If this happens in the real world it is not just one user complaining, but there is known malcode/malware to interfere with the normal Microsoft updates as with other av solution downloads and scans,