The Access Manager amtune script sets the com.iplanet.am.session.purgedelay property to 1, in order to allow as many Access Manager sessions as possible. This property specifies the number of minutes to delay the purge session operation. For clients such as Sun Java System Portal Server, however, a value of 1 might not be sufficient.
Workaround: Reset the com.iplanet.am.session.purgedelay property after you run the amtune script:
In the AMConfig.properties file, set the property to the new value. For example:
com.iplanet.am.session.purgedelay=5
Restart the Access Manager web container for the new value to take effect.