Downgrading from Cisco ASA 8.3

8.3 is the new major update from Cisco that contains so many philosophical changes that it should be considered 9.x.  Besides changing the way inbound ACLs are defined, they have also gone to a object based configuration and Natting has been revamped. Unfortunately all of the bugs have not been worked out yet and many people are downgrading. To make matters worse, all new appliances are being sent with 8.3 preloaded, which requires a conversion to get older configurations to work. To properly downgrade, the downgrade command must be used. Cisco has indicated that this command merely replaces some of the manual commands that are ran during a downgrade, like setting the bootsystem, write mem, and loading the config, however I have received confirmation that other steps are actually performed behind the scenes, that does not take place when a manual downgrade is performed.

To downgrade do the following:

ASA(config)# downgrade [/noconfirm] old_image_url old_config_url [activation-key old_key] 

Ofcourse this assumes that the old image and old config are on the appliance. If you received a new appliance 

and would like to downgrade, the image and config should be copied over first.