Imported old db to new test store install -- trying to upgrade & cannot log in

[lindagal2]

Test Store URL: https://teststore.frenchteachers.org/
ZC Version 1.2x (upgrading to 1.2.7 first)


Have been trying to upgrade store from 1.2x to 1.5.5e for a while but have consistently had trouble with db. I've installed a fresh install of TESTSTORE, then restore a copy of the current (working) store's database. All seems well, then the upgrade screen comes on and asks for superuser info.

I've tried entering the only superuser listed in the admin directory of original db (a copy of which has now been imported to TESTSTORE) along with the password. In fact, I used same pw for both database access and TESTSTORE superuser).

STILL gives me an error message:
"There are some problems
Could not verify the Admin Credentials you provided.

To authorize the database upgrade, you must enter an admin username and password with SuperUser (ie: unrestricted) permissions in your store.
This will be the username and password you use to log in to the Admin area of your store.
(It is NOT your FTP password, and is not your hosting control panel password. Nobody knows this password except you or your storeowner. You can not get it from your hosting company.)
If you are locked out of your store and do not know any valid admin passwords and cannot log in to your store Admin page, then you can do an aggressive reset of the password by following the instructions in this article: http://www.zen-cart.com/content.php?44-how-do-i-change-or-reset-my-admin-password."

What am I doing wrong? The superuser password works to log into current (working) store and I'm using an exact copy of the db in TESTSTORE. I've even tried the superuser pw provided in clean install, which didn't work either.

Help! (Thanks!)