Database Migration Problem

Try and do a nav backup and restore. When you backup, just select the data.

create a new 5.0 db and load the objects from a previous 5.0 backup and then restore the data from 2009 backup.

Get a standard unmodified cronus Database. And use those objects.

Then in your converted 2009 db. filter on modified objects extract them as text.
You need to remove 2009 tags. Then imiport the text in 5.0 and compile them.