Process Approver URL is not interpreted

I follow the Process Approver document to setup the url for accessing the ticket in notification directly.

http://community.landesk.com/support/docs/DOC-22102

I setup the url in System->Process Approver as below:

Enter the Web Access Process Approver URL :

http://LANDESKSD75/ServiceDesk.WebAccess/object/open.rails?class_name={Class/Module/Name}.{Class/Name}&key={Guid}

Enable Web Access Process Approver URL : True

Then in my reminder i put : {$ApplicationSetting.ProcessApprover.WebAccessApproverURL$}  in the body text.

However in the notification the url is shown exactly the same as what i configured in System, ie. :

http://LANDESKSD75/ServiceDesk.WebAccess/object/open.rails?class_name={Class/Module/Name}.{Class/Name}&key={Guid}

I tried to put the statement "http://LANDESKSD75/ServiceDesk.WebAccess/object/open.rails?class_name={Class/Module/Name}.{Class/Name}&key={Guid}" directly in the remind detail box and it will turn out as

http://LANDESKSD75/ServiceDesk.WebAccess/object/open.rails?class_name=IncidentManagement.Incident&key=f25200a4-b825-4a8b-970b-341d25e5b178

So it seems the placeholder is correct, the parameter  {$ApplicationSetting.ProcessApprover.WebAccessApproverURL$} works, but somehow it does not get interpreted when the reminder is saved. 

Does anyone know what's wrong with it?