Edit Incident: String entered in the 'Affected User' or 'Set Owner' fields should be passed through to the search window when clicking the magnifying glass icon.
Current behaviour forces users to retype whatever they had on the main form into the search field in the search subdialog.
This issue is fixed in ServiceDesk 7.6.
As a workaround, making the following changes to the SD.IncidentManagementSimple.Classification workflow will resolve the issue:
ServiceDesk 7.5 SP1