Computers with agents are going into PXE on reboot when no jobs are assigned to them
GSS 3.x
Open the PXE Configuration Utility and click on the 'GSS" tab
Toggle on : Enable response to computers with active GSS job assignments only
Click ' Save' and 'OK'
This will force the computer that has a job directed at a managed computer to effectively allow it to PXE boot. If there is no job then the computer system will boot into the production OS.