user created themes on OS X

Hi

I tried to follow the instructions for creating new themes carefully. I made sure to leave all the filenames intact and zipped (using DropZip) all the files and renamed them to zgreen_theme.lwtp However, even after restarting limewire my new theme was not visible. More interestingly, neither are the auto installed limewirePro_theme and windows_theme. then I thought I'd get really clever and rename my theme to green_theme (which i could use) after renaming the original green_theme to have the word original in it. Lo and behold, the theme menu now shows a green_original_theme but does not show MY green_theme. So obviously there is something in both my theme and the windows and limeworPro theme than the theme parser doesn't like. Any clues.

Oh yes, I'm working with Mac OS X 10.2.5

Thanks
John