I did set DHMI only as a source. After rebooting, projector just hang at boot up, only displaying InFoucs logo. I can not even power off the system, basically it is just stuck.
As per InFocus web site, New firmware 2.8 will correct the problem.
- System lockup on boot-up when only first item in Source Enable menu (HDMI) is enabled (all others disabled).

Since my system is already stuck in bootup, I can not upgrade the firmware.
Did anybody encounter similar problem. Is there a way to fix this issue?