This seems to be caused by __GL_SYNC_TO_VBLANK=1
I am running Solaris10 64bit on a dual Opteron box (w2100z) with
I can reproduce this effect whenever __GL_SYNC_TO_VBLANK=1
is set, be it just for one GL application or for the whole Xorg server
and all spawed processes. Although some applications do not seem
to induce the problem, others do.
For me, this seems to happen both with version 7667 and 7676 of