Windows Update KB936181 - Windows Vista Home Premium

The update KB936181 - Security update for XML Core Services 4.0 Service Pack
2 was installed in my computer by Windows Update, but the same update is
showed each time Windows Update has new updates, like it never has been
instaled!! If I install it again, it return in the next update.

I send the problem to MS ( SRZ080411000217 ) in April, 11th but they don´t
answer me.

Thanks,

Mario
.