How can i get [email protected] on a Samsung plasma?

You will have to use the VGA interface to send 1360x768 since the HDMI receiver chip in the HDTV will only accept standard ATSC resolutions such as 480i, 480p, 720p, 1080i, 1080p or some subset of these. Your Samsung user's manual has the information of what resolutions it accepts over what interfaces.

You will not suffer any loss of resolutin over VGA and you may not be able to detect any degradation of video color quality.

Thanks for your reply. I connected yesterday de htpc via vga and i do see a difference on colour and contrast. I just used a standard hdmi to vga cable. Are there "htpc" vga cabels out there that are better than standard cables? The colours are more vibrant via hdmi than vga.

AFAIK the cables have nothing to do with color quality. The difference is that you are converting the digital color received to analog color to send it over VGA and then your TV is converting the analog color back to digital. Therfore the quality of the color is affected by these two transformations. Since your Picture color settings are set and saved separatly for VGA as a source and as HDMI as souce you migh try adjusting your VGA Picture settings to improve the color quality.