CUDA driver for new iMac

I tried to run my CUDA app (with precompiled binaries for compute capabilities 1.0-3.0) on a new iMac with 675MX installed and the application failed to start. The application only uses driver API, so in theory only driver is required. It works fine on other Macs.

I used this CUDA driver 5.0.37.

The application could only start after installing CUDA Toolkit. I suspect that toolkit includes a newer driver which supports 675MX unlike the driver currently available for separate download.

Could anyone comment on this? Does anyone else have the same issue?