That monitor is 60hz&60hz interpolated to give 120hz for 3D stuff .. so your 60Hz looking laggy to you is a placebo effect and you've been sucked into the marketing crap and are now imagining seeing things which don't exist as 60hz is less than 120hz .. it's in your head.
As for the tearing type flickering, it could be a driver bug if you've eliminated all other options from the settings in VECC .. or it could be that that's what happens in non-3D situations and 60hz is optimal for normal usage ..
If card does same tearing on a normal TFT set to 60Hz, 75Hz or 85hz, then there's also a possibility of you having a faulty card. If you think it's faulty, send it back and if replacement does same, then it's an issue with your drivers or monitor settings or a combo of both.
AM3 965BE C3
/ 4GB Corsair XMS3 2000Mhz / GigaByte 990FXA-UD5 / Corsair H70 & 2 CM Excaliburs
/ x2 HD3870 ATOMIC Edition / Corsair 90GB Force 3 SSD / Momentus XT 250Gb Hybrid HDD / x3 Samsung F3 1Tb / Sony AD-7700 DVD-RW / Auzen X-Mystique / Enermax INFINITI 650W / Lian Li PC-7FNWB
/ Logitech X-530 / Logitech Kboard & MX620 Laser Mouse / Epson RX685 / DELL U2312HM 23" IPS TFT / MY RIG HERE