Another thing that I faced and it was seriously affecting my upgrade is the scripts that create a temporary tables.Apparently all the scripts that was supposed to create temporary tables did not work I could not create temp tables instead I had to create normal table that starts with tmp so that I could identify them and delete once the upgrade is done.This was so serious that I could not proceed without finding a solution for it.I know this may be it was my problem only but you can check to see if you have same problems.