Alienware X51 issues with Diablo 3

While playig diablo 3 just walking from one area to another or fighting enemies im having a skipping in the graphics. Im unsure what to do to improve this.
I've tried running the game on the lower settings.With more strenous games like battlefield 3 and planetside 2 on max graphics they run flawlessly. Does anyone
know what i can do to improve this? Thank you for anyhelp with this issue.

My game setting are settings are as follows on diablo 3

Resoulution 1920x1080
vertical sync on
max foreground FPS 150
Max background FPS 8
Texture quality HIGH
Shadow quality OFF
Physics HIGH
clutter density off
Anti-aliasing off
LOW FX ON

Operating System: Windows 7 Home Premium 64-bit (6.1, Build 7601) Service Pack 1 (7601.win7sp1_gdr.120830-0333)
Language: English (Regional Setting: English)
System Manufacturer: Alienware
System Model: Alienware X51
Processor: Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz (8 CPUs), ~3.4GHz
Memory: 8192MB RAM

Display Devices
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Card name: NVIDIA GeForce GTX 555
Dedicated Memory: 977 MB
Driver Name: nvd3dumx.dll,nvwgf2umx.dll,nvwgf2umx.dll,nvd3dum,nvwgf2um,nvwgf2um
Driver File Version: 9.18.0013.0697 (English) (306.97)
Driver Version: 9.18.13.697