If you just do a normal chown user.user somedir it won't work. You will see the ownership is still the previous owner.
How To Change Ownership Of Symlink:
The simplest part is just adding the -h which means no dereference so it applies the ownership on the symlink and does not try (and fail) to change ownership of the dereferenced symlink destination.
chown -h user.user somedir........
When running cudaminer once it tries to initialize the card the entire screen freezes. The computer itself is still running but the Xorg is done for, you cannot even switch to another console window and must reboot (even an mdm or Xorg restart does not help).
At first cudaminer will give you these errors:
...retry after 15 seconds
GPU #0: Geforce 210 with compute ca........