Hi,
The problem seems to be that the setup routine thinks it needs to do a clean install rather than an upgrade as indicated by the "database schema needs to be created" part of the output. The setup routine makes the determination of whether it is an upgrade or a new install by detecting if the mp_Sites table exists or not. So in this case its either getting an error trying to detect it or it can't detect it so it is trying to run all the scripts needed for a clean install.
I'm wondering what version of MySql you are running, my guess is you are running the very newest version 5.1 which I have not yet tested myself. Perhaps something has changed and tables need to be detected a different way or something. There was a report of strange issues with the rc of 5.1 before it was released.
What I would suggest is. Look in the mp_SchemaVersion table and see what current version of mojoPortal you have. Then manually run the scripts in sequence from the /Setup/applications/mojoportal-core/SchemaUpgradeScripts/mysql folder starting with the script version higher than your current version and ending with 2.2.5.4.config. You can skip any empty ones. After you run all the scripts set your version manually to 2.2.5.4 in the mp_SchemVersion table.
Please do confirm whether it works and what version of MySql you are using.
Hope it helps,
Joe