Hi, which SDK are you using?
I had stable OpenGL behavior with the older 1.0.1 SDK and the newer 2.0.0 SDK.
I found that the 1.1.1 SDK was quite problematic.
If you have 1.1.1 SDK, you should consider upgrading to 2.0.0 SDK.
When you upgrade your SDK, be sure to update your projects too.
Right click on your project > ArcGIS Tools > Fix Project Properties