This is more for end users.
When the auto-logout pop-up window asks if you want to reconnect, respond "yes". The login screen will then appear.
Enter your user ID and password. DO NOT PRESS ENTER.
Instead, go to the upper left hand of your screen and click on "user", then click on "Copy Session". This will bring back up any sessions you had open with the same screens and materials you were working on.
It appears that this is only effective for approximately 45 minutes after auto-logout occurs, at which time the buffers are cleared.(We are on SAP v4.5B with our Production instance set to auto-logout after 45 minutes of inactivity).