Jeff,

I've also seen similar activity, but only a reboot will restore the
screen/framebuffer. Unfortunately that's where the similarity stops
with our hardware. I'm using dual XVR-2500s, with NEC 20 inch and
Eizo 24 inch monitors. The blanking rarely, if ever, occurs on a Sun
24 inch monitors. So it's possibly some compatibility between the
hardware and/or power management functions.

Blanking has been SIGNIFICANTLY reduced by continually updating the
XVR-2500 drivers when they are released from Sun.

So ..... ensure you have the latest XVR-100 drivers installed as well.

Chris