OS X :: Can't Compress (.zip) File (RapidWeaver Theme To Email)

I'm trying to compress (.zip) a RapidWeaver theme to email. The theme is a package of other files and folders including images, stylesheets and scripts. There are no other compressed files within this package or Flash files. When the file has been saved to my desktop, I right click and select "Compress" from the menu. The progress bar gets about 2 thirds along and just freezes. Evidently there is a corrupt file or something in this package, because I have never had this problem before. The package is only 1.6MB in size.

There are about 150 files in this theme. I have looked for any suspect messages in Console.app to try and work out which file is corrupt or causing the problem. But nothing seems to be shown? If I compress the RapidWeaver theme as a GZip file using TarPit, it works fine. But this does not solve the issue of somebody else trying to compress the sent file and hitting the same problem. So my question is how can I work out which file in the package is causing the error?