clJobQueue
What does cl stand for? Class? It looks like some weird form of Hungarian notation, you shouldn't use that.
clJobQueue.Instance
Why is it a singleton? If you want to be able to easily access the queue from multiple places in your code, then a static class would work just as well. But I think a normal (non-static, non-singleton) class would be an even better option, since that means you can have multiple queues in your application.
clJobQueue.Instance.Populate()
Why does the queue know how to populate itself? I think that a better approach would be decouple the queue from getting the jobs, and have some external code that calls Add() on the queue.
Because your Parallel.Invoke() calls methods that don't return (at least not until they're explicitly canceled), it will never return itself. This means that your Ctrl+C-handling code will never be executed and that pressing Ctrl+C just terminates the application as it does normally, it won't cause Stop() to be called.