MGcam should be set to auto-start meaning if your box crashes or reboots it will just start. If the auto-start is on then try uninstalling and re-installing MGcam as it may have been corrupted or something or if your using MGcam 1.38 downgrade to 1.35a or visa versa
Menu --- > SoftCam / CI --> Softcam Manager --> Blue button to set autostart