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.