If you have two GPU's in your notebook, it's best that you install the latest drivers for both of them. Then, in the nvidia control panel via right click on your desktop, you set the default GPU to NVIDIA for all 3d applications.

If this is not related to your issue, please send us a report.zip from our support tool.
It can be found here: http://www.larian.com/OriginalSinAlpha/AnalysisTool_DOS.exe
Simply run the tool and click generate report, then send this to supportdos@larian.com with a small description.

Thank you