Dear modulers, There are two Heap modules: /modules/by-authors/id/MJD/Heap-0.10.tar.gz /modules/by-authors/id/JMM/Heap-0.01.tar.gz These are very different, and one of them is required by Jarkko's graph modules (JMM's). A search for "Heap" on search.cpan.org only turns up MJD's module, presumably because it thinks they're the same module, and MJD wins out on version number. Since JMM was there first, and there's a module depending on his, I think MJD's could do with a rename? Neil