Here you'll find a d/l for 27.42 with "refresh rate fix" built in:
http://www.mediaxplosion.gamigo.de/downloads/treiber/nvidia/nvidia-s1.htm
A manual FIX, so that Nvidia 27.42 WILL work with the said Refresh RateFix progy, can be found here:
h**p://www.geocities.com/tikimotel/nv4-disp.zip (copy/paste, then retrieve file)
It involves exchanging the re-edited inf file into the 27.42 driver release.
In case anyone cares, I found nvidia ver 26.53, which works fine with nvreffix (build 169), also produces the highest 3Dmark2001 scores, compared to ALL other Nvidia drivers released/tested so far. The 27.xx drivers, I've found to be slower, unstable & problematic, besides this nvreffix issue. (sys: WinXPpro, P4, GF3T500)
Eventually, a good stable 27.xx driver will emerge.
Also, the author of nvffix:
http://www.planetquake.com/ztn/nvreffix/
is working on a fix for his progy to work with the 27.xx series.