I tried it too, and I'd say it worked out pretty well.
But the 'Effect'-Lines look a bit weird..
And I also suggest 'Average Blurring' every layer of the CP, it looked great for me.
My Try:
Hmm...
I don't know that much about Paint.NET, but I guess you did something wrong with the curves.
I also have a question myself; can I make the background transparant?