We have an app that works in our Windows testing VMs on Windows 7 and Vista, 32 and 64 bit. It's using the PHP module. On one laptop which we've attempted to run it on, it crashes immediately on startup. A little experimentation has revealed that it's the PHP module causing the crash; when it's commented out of the manifest the app fires up just fine.
Desktop app? Mobile App? Android or iphone? iphone SDK not available on Windows.
Sorry, it seemed so obvious when I was writing it, now rereading I realize how vague I was. This was a Desktop app.