To disable autosave version on Mac os x lion, you should do as following steps:
Step 1--Open ‘System Preferences’
Step 2--Open the ‘Time Machine’ menu
Step 3--click the ‘Options…’ button
Step 4-- Uncheck the box “Lock documents [drop down] after last edit”
Step 5--There is a description on the option below it, saying:
Prevents accidental changes in applications that support Auto Save.
Step 6--So when unchecked, it should turn off Auto Save.
Try this way, you can easily disable autosave version on Mac os x lion. Good luck!