• How to update Web2Py?
• Updating Model in Production: ​http://groups.google.com/group/web2py/browse_thread/thread/5bda2edef0ad656d
• ​PyTZ will need to be updated if the system will be used in timezones which change
  

Note :

1) The databases directory contains what web2py knows about your database
2) You need to set Migrate=True in models/000_config.py before you update the code and switch back to Migrate = False later on.
3) In case of database mismatches - check the databases directory for the appropriate table ( cat the file ) and change accordingly.