It is about Windows XP Pro SP3
April 2009 patches applied for all MS applications, including those for OS.

After April patching completed the visiting and verifying patch status
using Windows Update Portal results in following findings:
KB955839 day light patch missing
KB952287 MDAC patch missing
KB951978 VBScrip/JScript patch missing

Verifying the current patch status using MBSA results in following findings:
KB955839 as above
KB951847 .NET patch missing

Verifying using Secunia PSI doesn't result in any findings.

Where these discrepancies from?
Especially those between Windows Update and MBSA results?