I forgot to log on before send this replies, sorry!
I made upgrade for 5.01 last month and I didn't have problem.
It was so easy and friendly. You have to make backup for everything
(forms and records) in order to go back in case of trouble.
During installation it will ask for Upgrading /overwriting, don't forget
To chose "upgrading".
You can also choose to overwrite the
database, which creates a new database, and overwrites your
existing structures.
Good Luck!
Lino