Brian

For anyone else that's having this problem (and hasn't submitted a ticket yet), just run this query through phpMyAdmin or in your Admin CP:

UPDATE adv_setting SET value = '1.0 RC4' WHERE varname = 'gallery_version'

Then go back to the install script in your browser, select the option to upgrade again, and that should allow it to finish the upgrade. The install script has also been updated on here so that others won't have this problem when they first try to upgrade.