An NVidia developer tracked this down to bug in the X server:
http://cgit.freedesktop.org/xorg/xserver/commit/?h=server-1.5-branch&id=75b5e999f045524e2b362e848a0104e1a4217061
An NVidia developer tracked this down to bug in the X server:
http:// cgit.freedeskto p.org/xorg/ xserver/ commit/ ?h=server- 1.5-branch& id=75b5e999f045 524e2b362e848a0 104e1a4217061