We have found the problem and have a fix. It is _not_ a graphics driver problem, it is in our graphics layer code.
The problem is caused by the graphics HW using all its available video memory for graphics windows. The Quadro FX 330 has 64 MB of video memory so if you create several large graphics windows, even at 1280x1024, you will consume all the video memory available.
When this happens, Direct3D will correctly report a failure to optain more video memory for the next graphics window. We were neglecting to propagate this error condition up through our code so our graphics window code would respond accordingly.
With the fix we have just implemented in our Development code, we have verified that we now handle this error condition properly and the Inventor graphics windows work correctly.
The work-around in the meantime is to avoid having several graphics windows open at the same time. In our testing, without the fix, we could open 7 graphics windows before the problem occurred. With the fix we see no limit; for example, we have tried having 60 graphics windows open at the same time without seeing any problem.
Thanks to all who reported this problem and helped us track down the source of the problem in our graphics layer code.
Norbert
Norbert Jeske
Graphics and Visualization Technology Lead
Autodesk, Inc.