[Koha] Available items limiter: No Result found ! - Common Problem

Hi, I have noticed that several Koha website gives the same error message: *No Result found ! N*o results match your search for “ ..." when a Koha OPAC user tries to limit search results by the Available items (currently available items<http://badir.maktabat-online.net/cgi-bin/koha/opac-search.pl?q=software&limit=branch:Shaf&limit=available> ). We are running Koha 3.00.5 on Debian. Does anyone have a fix for this (apparently) common problem, or understand its cause ? Thanks Massoud M. AlShareef, KnowledgeWare Tech