Yes, it can be done. The setup requires some reading, and manual editing of the config files for X. See the readme for the driver version you're using, available on the nvidia site (check the list of appendix topics for twinview). See the manpage for X config at:
I don't have a second monitor so I have never set this up. When you've read the material try to ask specific questions regarding your setup, and include as much information (and copies of your current config / logs). Open questions are hard to answer in a way that will help you.
"..the triumph of evil is for good men to do nothing."
VIDIA video driver RPMs for Fedora
:: see yum repo at livna.org