I've inquired some more about this and as I understand it, the Gnutella network does not support ( ) ^ { } [ ] _ ! symbols and one or two I may have omitted, and whilst it is quite possible to compile Limewire in such a way as to remove these apparent omissions, the excercise would be fairly pointless for the reasons I have already given.
fwiw, I have always found searches work quite satisfactorially without the need to insert these items in to a search.
I hope this explains the situation
