This week i'm migrating a SPS 2003 portal to MOSS 2007 using the DB Migration model.
One of the problems that a i had was that in some sites the url was /pages/UpgLandingPgRedir.aspx.
To resolve this issue i needed to go to welcome page on site settings and change the url to default.aspx, on each site that had this problem.
So i've developed a console application to change all sites welcome page url's from UpgLandingPgRedir.aspx to default.aspx :).
Later i will add the download link to this post.