I had the same flicker problem on 3 different machines with different cards, GeF4-MX440 dual, GeF4 4200ti, and the GeF FX5200. Your solution worked on all 3 machines. I think the flicker problem started when I upgraded to the 2 last driver versions. I wonder if this caused the one monitor to die last week..
I still have another odd problem on 2 of the machines. This started the same time as the flicker. The 2nd monitor goes blurry at times. It does not happen on the machine with the GeF4 MX440 Dual card, just the ones with the DVI output. I am going to go back to 4996 driver on the MX440 and ti4200 setups. I guess I am stuck with the FX5200 until a better driver is released. I do not want to lose another monitor.