i would try to examine the problem from the OS side: Is your file system ok? Is the login you're using ok? Are the folder permissions ok (i.e. is limewire able to save into the save folder)?

Considering that you repeatedly uninstalled and reinstalled LW, it is unlikely that it is limewire.

You could try trashing limewire.props, it's in Documents and Settings/Users/whatever your login is/.limewire

This file holds the folder settings and if you trash it LW will revert to the defaults.

good luck!