Cassette does not include files in /fonts and /images.

I have a web app that works fine in debug, but does not load any files in /fonts or /images that are included in css url() in production. When there is a css rule that says url('../fonts/file.woff') cassette turns it into ('/cassette.axd/file/fonts/file.woff-hash') but there is no file there. How can I get cassette to include these fonts in the bundle in production? Please answer ASAP.