OP - you haven't mentioned which AVR you have, model specific..........Are you using onboard graphics (i.e. intel HD2000/HD2500/HD4000) HDMI out? If so, do you have the latest drivers? If using a graphics card - are your drivers up to date? Also, have you tried a different HDMI cable? One that is 1.4 compliant?
Denon AVR-3311CI, Denon DVP-602CI, B&K EX4420, B&K TX4430, Belkin PF60
Sony BDP-S5000ES, Silverstone HTPC (6 Tuner DVR & 10 TB Media)
PSB Stratus Minis, PSB Stratus C6, PSB Alpha S surround, James Subwoofer EMB-1200
Sharp LC-70LE755U, Harmony 880 Remote