> 	Which version of FLTK (1.3.1, 1.3.2..)

I use FLTK 1.3.2
>
> 	Also: do the FLTK opengl test programs cube.exe and shape.exe exhibit
> 	this same behavior?
>

Yes they do.


> 	I cannot replicate with Win7 + mingw-64 (gcc4.5.2) + fltk 1.3.x-svn current;

I am using the 4.7.2 rev 9 with Win 7

> 	Hardware is a mac mini running win7/64 ultimate, default drivers.

I use a Dell precision
>
> 	If you're getting this behavior with all the GL demos,
> 	try downloading GLUT and see if their demos do it too.
> 	If so, it's probably your GL drivers. If not, let us know..
>

I am wondering about the drivers also, but I cannot say for sure. I did upgrade my drivers before posting just to make sure, but still it is strange that I cannot see this behaviour on any other opengl program.

I did download and compile freeglut, their demos run smooth without any problems.