Thanks for the ideas but none of them worked - however - what I ended up doing was to delete Limewire 4.9.30 completely and then install LimeWire 4.9.33 and, instead of running as compatible with Win. 95, selected Win. 98 (I am using XP for which there is no option).
My files were still not being shared but by right clicking on 'Shared files' in the Library options I was able to add the folders that were missing.