If you have the same version of realplayer which I have (10.7), it will be dependent on libstdc++ version 5. This is not installed by default on many distributions, so check your package manager. On Debian and Ubuntu, the package is called libstdc++5. I'm not sure about centOS.
Try running real player from a terminal and seeing if you get an error message. If you have the same libstdc++ library problem, that should be clear from the error message.