As having been bitten by the spaces-in-filenames issue (again) this weekend on Mac OS X, I would like to point out that scripts need to handle filenames with spaces correctly.

Or you Mac and Windows people need to stop getting creative with filenames. :)

As an actual solution, you can try using xargs -0 in such situations on OS X. Get a copy of ppt's (Gr. That should link to PPT, not to some search results!) xargs if you're on a Windows machine.