I emailed Avast tech support about this issue, and got this reply:
<<We are, together with Microsoft, trying to find where this bug comes
from - once found,
the patch will be available via regular avast update.>>
"History Fan" <IreallyHATEspam.RemoveThis@iREALLYhateSPAM.com> wrote in message
news:GvCXd.2933$S61.2449@fe37.usenetserver.com...
> I have a computer running Windows XP Home SP2. My AV is Avast Home
> Edition, build number 4.6.603. Yet XP Security Center reports that I'm
> using build 4.5.603. I recently formatted my hard drive, and the only AV
> I installed was the latest version; hence XP should not be able to find
> any trace of version 4.5.
>
> Is this customary with other Avast and XP users? If so, why the
> discrepancy?
>
> >> Stay informed about: Avast build number and XP Security Center