Microsoft Update Continues to Offer SQL Server 2008 SP1 Update

XP Pro SP3

I recently installed SQL Server 2008 Express SP1, but Microsoft Update
continually offers a 'Microsoft SQL Server 2008 SP1' update. According to
the version no., SP1 is already installed.

At first, I tried to update with Microsoft Update. It would tell me that it
was successful and would indicate so in history, but the next time I
visited, it offered it again.

I decided to use the SQL Server 2008 Express SP1 version by hand, and after
several errors I finally got it to install. Perhaps Microsoft Update
doesn't know how to handle the errors that it encountered. Some of them
would probably be popular errors.

MU still, however, displays the SP1 update. What's the deal?

Please help.

Fred