OpenGL ES problem on N73

I've recently got an N73 from my company. Since this phone (or mobile computer if you prefer to call it this way) includes a software OpenGL ES renderer, I'm eager to try if the sample programs included in the Nokia OpenGL ES 1.1 plugin run on a real device. After I compiled a very simple sample SimpleCube and installed it on my N73, the testing result is disappointing because the rotated cube flickered all the time. I googled but haven't found many useful information for this issue. Later I found that the problem is caused by fast periodic refreshing. The timer in the example is set to 100 microseconds. However it seems that the software renderer can't finish the rendering in such a short time. Therefore the next frame starts to render before the first rendering comes to an end. By setting the timer (the second argument of CPeriodic::Start) to 30000 microsecond, the animation now runs very smoothly. Hurah!