Looks to me that you have not run the PRESCAN tool on the MOSS server, which
is going to be necessary if you want to restore that V2 database to this
farm.

The MOSS Farm is detecting that prescan was never run on this farm, and is
required before any type of upgrade so that the MOSS farm.

How do I run the PRESCAN on the moss  server. When I execute prescan there, I
get this error:

PRESCAN.EXE /all http://mossserver:43468
This program requires Windows SharePoint Services v2.

and I never installed  2003 on the target server. It was a straight 2007
install. I did ran the Prescan on the source 2003 box though, but I would
doubt that doing a backup and restore to the target would carry the prescan
information.

Again, these are 2 different servers and I am using the DB migration to do
the upgrade.

This could be something specific to a content  database with a Portal site
collection in it.

But I don't have a definitive answer for you on it. Perhaps someone else on
the list can confirm/deny that for the Portal site collection, you "have" to
rely on a sidebyside migration.

Otherwise, what I would recommend, is if there are team sites in that
database, place them into a different content database, then move it to your
MOSS server, and for the Portal site collection itself, looks like you're
going to need to rely on a side by side for it

You could then move that upgraded database to your Pure MOSS 2007.