VTiger 5.2.1 to 5.3 Migration Issues

We have recently tried to upgrade our vtiger and it has failed. Despite numerous atempts to get help via their forum site we still cannot get the upgrade to 5.3 to work. The migration process failed to update some tables and therfore did not complete. We have managed to revert back to the 5.2.1, but it is not all functioning, we expect due to some table changes to the database. We did a dump prior to running the migration as they suggest, but have been unable to reload this into a new database to do further testing. So for this project we need someone that can sort out the migration to 5.3, and our database to get vtiger fully operational with all our current data and documents so we can continue to develop the CRM to suit our application. (The successful person could well be used again to provide some customisation after christmas once we have set out all our processes, but would be required to at least get the "cron jobs" working as well as the leads forms and customer portal, but that is not part of this project.) Vtiger experience is a must for this project and work must be completed in a timely manor so we have our system working again ASAP. We have a copy of the dump file together with a copy of the complete folder prior to running the upgrade which should allow for all the correct documents etc to still be available after the migration has been successfully competed.