Updating Driver On Osx Leopard Cannot install driver - installer blocks.

I’m attempting to update the CUDA toolkit on my MacBook, running Leopard 10.5.8, to CUDA 4.1, from CUDA 3.1. I downloaded the SDK, toolkit and driver, deleted the old installation, and unpacked. The SDK and toolkit install were straightforward. After starting the driver installer and accepting terms, the installer then offers the option of installing for all users. Unfortunately the “continue” button is then disabled, and I can’t progress.

Looking on the forum, someone posted a similar problem in Aug last year, and the suggestion was that the OS needed updating. My OS has all software updates applied, so the questions are,

  • does the CUDA 4.1 actually install at all on Leopard, or does it require a later OSX release? [I’ve been holding off updating the OS as I expect to upgrade h/ware in a couple months].

  • if it doesn’t, what is the latest version of CUDA / the OSX driver that should install on Leopard?
    [I’ve tried looking at earlier driver releases, 4.1.9 for example has the same problem].

  • if 4.1 should install, any suggestions on what is causing the installer to block, and how to remove?

thanks in advance.