R12 Teleservice task assignment manager

Hi,

I am trying to resolve an issue in R12 whereby the assignment manager no longer finds any available resources for service request tasks (the version of AM we are using is not the scheduling advice one).  If I untick the Resource Availability tickbox, the resource and shift (yellow box) do appear but without any slots (green boxes).  Prior to R12, AM would bring back the available slots and by double clicking on the relevant resource (in Gannt or table view) it would populate the resource name with a start and end time that fell within the planned start and end date window.