GraphicsEnabler=YES you will have proper frame buffer = VERVET and everything works as it should be for 5770 card. (HDMI not working in your case)
The problem is you are trying to use HDMI port and had to switch to GraphicsEnabler=Yes
GE=No will result in no proper frame buffer loaded and your DVD player crash and display profile = ATI Radeon 5000 (not 5770).
i have Powercolor PCS+ 5770 currently running 2 monitors via DVI. I do not have HDMI device to test..so I cannot confirm.
BTW, are you just trying to achieve Video via HDMI or both Video + Audio?
Have a read here for Audio..(if interested)
viewtopic.php?f=162&t=22031