Intel should say that hd 4000 graphic IS NOT SUITABLE for any HTPC environment. I have the same problem and unfortunately I've been reading about this after buying my i3 3225. I've read that older processors had the same problem and intel never solved it. Every time I start my pc I have to set ycbcr and ALSO when i do a restart I have to open and set the audio output property if i want an hdmi sound. Colours are wrong, black level and contrast are poor if ycbcr is unchecked. My htpc is not usable and now I have to reinstall everything on linux.
My pc:
intel i3 3225
asrock h77m-itx
4+4 gbRam DIMM DDR3 G.Skill PC 1600 CL9 Ripjaws
SSD 128GB Crucial Sata
windows 7 ultimate
denon AVR-2808 (it has ycbcr setting)
Regards.