Shy, I had the same issue and KRD helped me fix it.
1. Go to Control Panel
2. Go to NVIDIA Control Panel
3. Click the tab that says "Manage 3D Settings"
4. Click "Program Settings"
5. Select WA.exe from the list (if it's not there, click "Add")
6. Scroll down the bottom list until there's "Vertical Sync", set it to "off"
Lags should be fixed, it worked for me with a comparable notebook. The only problem which I still encounter is that my FPS drop to ~10 whenever a skunk's poison is released. But I can live with that. xD