Don't know if this is any comfort/help Daniel but I run my G91 thus;

Component out to TV (37in LG LCD max res 1366 X 720 I think) and HDMI out to my projector (JVC HD350). I've set the component out to scaled and the HDMI out to 1080p and get great images from both.

I did have a 'slight' issue when I first connected the HDMI cable in that I got no picture at all and the projector wasn't showing any input from anything. This turned out to be a directional HDMI cable so I had to crawl around my attic (again) reroute the cable through the built in media centre and bingo! Oh how I laughed...........

G91A, DSP5200, AC Ryan media streamer