Cuda 3.0 should support all cores but many cards like the GTX 460 have problems running with cuda 3.0. So if have to go with Cuda 3.2 not all cores are supported with your GTX 460. It is not really a bug. It is more some kind of changes in the program structure of Cuda.
The next beta release will support all cores of GTX 460 but only supports one card

. There will be an alternative version wich will not support all cores but multiple cards (like it works now).
So if you run 4 * GTX 460 it is a bit like riding a sports car with a speed limit of 80 km, but hey there are people who ride jeeps in the city and don't complain - Strange world.
So as (multiple) GTX 460 owners we have to wait another few weeks to celebrate.
I am sure Refractive Software and Nvidia will work closer in the future, so that Refr. Soft. can develope their updates with the actual Cuda structure before the Nvidia Cuda release.
Refracty