The machine connected to this monitor is a eMachine T3882, with all of the security tools and SP2 installed. Maintenance is done regularly and everything works perfectly, and much faster than an new, expensive Sony Vaio at work.
The last time it did this was in OCTOBER of this year. Before that, it did it one time in JULY 2005. You will be working and then the monitor's OSD screen will flash onto the screen (as it would if you pushed the top button on the monitor) and than change colors (just as it does if you would push the bottom button on the display to adjust the menu) and than go away. It did this for about twenty minutes - every three to five seconds - and then stopped. The monitor is a KDS 17" CRT, model #KF-7b.
Another machine in 2004 had the same thing happen, but it went on so much that the monitor was replaced. That machine is working very well in another office with no troubles. It is a XP SP2 machine as well.
As a network administrator, I have seen a lot of strange things on my machines...but this is tops!