Why is IronPython startup time so slow?

I've been using IronPython for a while now, but something which really hampers my development is that it is excruciatingly slow to start up. I love the language and its way of working, but it is frustrating to have to wait upwards of 20 seconds before it starts executing my code.

I have done some digging and it seems to be that the problem is not with the importing, but before that stage.

Thanks.