May have bug in u5
For those running solaris 2.7 on sun ultra sparc 5, when you have screen saver set to default it is on power saver's blank screen. What I've noticed is that the monitor control can pop due to faulty signalling.
Solution: set your screen saver to anything but blank screen.
Interesting. What monitor are you using? I run Sol 2.5,7,8 on U5s and I've never seen that. I'm using Sun 21" monitors.
Sun 17"s on all our boxes. I have used the larger ones at other companies and never had a problem even with the early versions, but on these I think its the control set.