1) Always list your vicidial version with build (especially when discussing upgrades!)
2) you keep saying "password" but remember: it's not JUST password, it's user and pass. if you use the ROOT user, you'll need the ROOT pass to go with it. easily tested (mysql -p). if you are remembering the "cron" pass being 1234 ... remember that cron should not be able to modify the structure of the database ... so you should be using root instead when updating the mysql tables.
3) i've had many instances where a mysql command line fails during the upgrade. generally deleting the offending lines and all the lines before it (because they've already run) will suffice. usually it is the addition of a field or index already present or a removal of one that has already been removed. often you can check your dbschema value in system settings and remove any entries in the sql upgrade file that are earlier than that dbschema value (look for the dbschema upgrade sql command which occurs rather frequently).
but DO bring your brain: if the item that failed may be necessary, you may have to alter the query to allow it to work. i've not bumped into this recently, but it is possible.
when in doubt: bring the offending command HERE and ask