So it's very much worth your while to explore every other avenue and if
you truly cannot find anything wrong at your end, make life as easy as
possible for the guys at nVidia. eg: Get this to work in a GLUT
application
instead of SDL - use a *simple* Makefile and link as few other libraries as
possible, make the code be as simple as it can be and yet still exhibit
the bug, give them a concise description of the problem, the hardware you
used, the driver revisions and any information about how it behaved with
other driver revisions - explain that the problem happens under Windows
as well as Linux, try to get someone to run it on an ATI card and hopefully
be able report that it works OK there.
That way, the next time you need their help, they'll be more likely to
give it because they'll get to know you as someone who doesn't cry
'Wolf' and they'll come to respect your abilities and actually value
your bug reports as genuine contributions.