Monkeypatching native types looks suspect as anything, but probably not the cause here. Good luck :)

So I checked some of our code around dynamic loads and it's got to be caused by the loader in our LoadLibrary call, not when we call your module init function. That rules out basically anything you're doing once the module is loaded.

The only thing I can think of that may be missing in the .pyc case is encodings. They *should* be being imported automatically on load, but perhaps not as we're constantly trying to improve startup time. You could try adding "import codecs" and then codecs.lookup some codecs.

You might also try running Python in verbose mode ("python -v ...") and comparing the output between the two cases. That could show up what extra things are being skipped in the failing case.