Hi, you have installed vers 2.7.3 ??
The installer is buggy and creates in your LimeWire dir a subdir Limewire.probs !!?? it should be a file instead. Delete the subdir and create a new file limewire.props place it in the LimeWire dir . Restart LimeWire and go through the startup-procedure for the last time, it should store your settings now in the limewire.props file.