yes at 720p all is ok, no slowdowns anymore, but this white snowing effect even if reduced is still present and noticeable, i've also big problems of aliasing i think, i have to ask if wipeout HD have anti-aliasing or not cause in my game there isn't a line who isn't squared distort and jagged like the ones you do with microsoft paint...

my cable is 2m long gold plated 1cm thick, but i've pay it 15 euro so it's likely a cheap price

so you're able to confirm me that all these problems have to do with signal loss , caused by hdmi cable and not hardware problems?