I saw over at the NVmax site that another version has been released. It is recomended that you upgrade to this version. Heres why:
The following problems have been addressed. It is important that all users upgrade to make sure they dont get any of these problems.
:: Fixed complete program failure on Windows 9.x/ME based systems (complete function failure).
:: Fixed problem whereby no settings would save on Windows 2000/XP. This bug would not effect Color Control or Overclocking.
:: Fixed problem whereby OpenGL FSAA would not report a value.
Due to the extremeness of the two uppermost bug fixes I highly recommend users upgrade. On another note, NVmax is now driver independant so if NVIDIA changes the registry locations in future drivers NVmax will work correctly.
Download: 3.00.53
News source: NVMax