I asked for help from NVIDIA, got nothing (he suggested trying different modes, but I already tried 4 different settings) ... I tried swapping monitors and it follows the plug - unless there is a cable problem
I have noticed that the blink happens often when I move mouse - this may indicating something caused by window manager/X server
What is your setup - maybe we can find something common ? Did you try the hardware in Windows ?
I use gnome + sawfish, and I am really back with Linux version - because of the need for stable build environment I keep RedHat 7.3. XFree86 version: 4.2.1, NVIDIA most current, I consider upgrading to RHEL 3.0 and also changing mbrd at the same time (both low end, but the next should support more RAM). I may also try the famous 4620 drivers and play with settings there.