First, what distribution do you mean with linux 7.1? As far as I know there are at least RedHat Mandrake and SuSE with an 7.1!
And then, because of security reasons I would never dare to launch a filesharing software with root permissions and I don't think you have to do that.
As for me on a Debian system, I've installed LimeWire as a normal user under my home directory and to start it I simply use 'sh LimeWire &'; no dealing with permissions, and it works for me.
Eventually, if you've installed it as root, you could try to make the user the owner of the LimeWire subdirectory and its files. E.g. if you have installed it in /opt/LimeWire and the user Joe in group audio should use it, do something like 'chown -Rc Joe.audio /opt/LimeWire'.