Koby,
What you're describing is not normal behavior so I can't explain your particular experience. I suspect it could be due to your "crash" which resulted in some corruption to your database. In particular the data elements the system looks for when you attempt to do an update or install. During a new new install or an update of AC, the installation program looks in the database for certain values to ensure you are authorized to to perform the install/update. If you're installing AC for the first time on a new server there is no database so you always need a key from CS to proceed. The key is not stored locally and is unrelated to the new encryption, it's simply a temporary key to let you proceed with the install/update. Existing users performing an update should never see the prompt unless they have some database corruption or their Guardian Angel Support has expired. If they do not have active GAS then they are not entitled to receive the new versions.
Bert..to answer your questions, the pre 9.1 enc files being sent in today to CS are HIPAA compliant as far as the encryption goes. We just made it better to stay ahead of the bad guys who seem to be getting smarter every day. In regards to the Support techs response...They are probably not thinking in terms of .enc file versions...it's extremely rare that the need arises for us to re-encrypt a file. They are speaking in terms of the "same machine" or server..The .enc file you restore must have originated from the same physical server from which it originated, or you need the secret sauce.