The ruby version is ruby 1.8.6 (2008-08-11 patchlevel 287) [i386-mswin32] The OS is Win XP The first piece of code is called as lines below from another class zip_file=3D ZipUtils.new(@file_names[file_index]) zip_file.createkmzfile -----Original Message----- From: b.candler / pobox.com [mailto:b.candler / pobox.com]=20 Sent: Friday, February 26, 2010 2:24 PM To: ruby-talk ML Subject: Re: Class Function call vs Normal Function call Your first piece of code doesn't do anything at all, because it just=20 creates a class ZipUtils but does nothing with it (never instantiates=20 it, never calls a class method). Please make two complete standalone test programs to demonstrate your=20 problem. This means that (a) we can see if we can duplicate your problem on our own machines, and (b) we can tell you why it's not working as you expect. Or you may find in the process of making these standalone=20 problems where the issue lies. It's also useful to know what version of ruby you're running under, and=20 what O/S. --=20 Posted via http://www.ruby-forum.com/.