I've not really heard of anyone flashing their monitors, but I know that it's possible. The only reason that I've heard of doing that is to repair corrupted EDID data. I suppose one to use it to "tweak" their EDID data to workaround the bug in NV's drivers for driving the 6800 connected to a DVI LCD with funny refresh-rates listed. But later versions of the NV drivers are supposed to fix that problem.
Are you sure that you don't mean, updating the monitor .INF driver in Windows'? All that does is inform Windows' what the safe set of resolutions and refresh-rates are for your monitor.