While disconnected from the network attempts to unlock the screensaver fail.
By default the disconnected cache is stored in /tmp on all systems. OSX systems routinely clears the /tmp folder of files.
To resolve this issue store the disconnected cache in the user's home directory.
On individual systems this action can be performed using a configuration command.
/opt/quest/bin/vastool configure vas vas_auth nonroot-disconnected-cache-dir %homedir%
Alternatively this change can also be configured in Vintela Group Policy so all machines will be changed to the new location. In the policy select "Unix Settings" | "Quest Authentication Services" | "Client Configuration" | "VAS Configuration". Expand the [vas_auth] section. Locate "nonroot-disconnected-cache-dir " and place "%homedir%" (without the quotes) into the field.
This only affects OSX 10.6.
QAS 4.0 stores the disconnected cache in the user's home directory by default.