Visual Studio 2005 - Web Installer with corrupted CAB file

I have a project that's built by Visual Studio 2005 (via CC -> nant) and generates an MSI file for a web project. Every once in a while it generates an installer that contains a corrupted CAB file, I have no idea why. Google isn't providing any pay-dirt either.

I'm going to upgrade the build process to VS 2k8 in the hopes that will help make the problem go away. As it only ever happens with 1 of many web project builds, I'm not getting my hopes up :-|