In ISA Server 2004 and 2006 there was a difference in the behavior of configuration changes between Standard Edition and Enterprise Edition.

In Standard Edition, the configuration change operation was synchronous. This means that applying the configuration completed after the new configuration was stored and loaded by the ISA Server computer (which was always the same computer).

In Enterprise Edition, the configuration change operation was asynchronous. This means that applying the configuration completed after the new configuration was stored to the configuration storage server (CSS). However, for the configuration to take effect the array members still had to read the new configuration from the CSS and load it.

In order to check if the configuration reload was completed, the administrator needed to check the configuration status tab in the ISA Server console, as in the screenshot below (taken from a Forefront TMG computer):

http://blogs.technet.com/b/isablog/archive/2010/07/18/synchronous-configuration-changes.aspxclip_image002