Open /tmp/novell_access_manager/ags_install_2010-07-12_14\:38\:35.log file.
See the certificate error (For example - invalid/expired certificate).
Look for successfully wrote:keystore message.
To workaround this issue re-import the Access Gateway into Administration Console.
If the time is not synchronized between the Administration Console and Access Gateway, then synchronize the time and re-import.