I've seen several post like this one but no solution I've seen for my problem.

I always use DrByte's suggestion for upgrades. I upload all the files to a new directory on the site/server, I create a new database, I make a backup of old store and restore on the new one created for the upgrade, then I run the install.

I'm stock on this last page when the db is patched. I haven't upgrade any 1.3.9 to 1.5 (although I have installed 1.5 before). This database (old store) has 3 users/passwords. I've used the 3 of them without success. I get over and over the message Admin Password required to proceed with upgrade.

At the beginning I got:
-PHP Safe Mode = ON
I don't know if that hast to be with the failure but I'm notifying it. (I will work on this with customer though).

Any idea of what could be wrong here?