Hi Chris,
Are you sure the contact form is still working?
Is it possible that you have set DisableTaskQueue to true in config? This particular email is sent from an EmailMessageTask that is queued on a background thread, so if the taskqueue was disabled it would not send anything.
Anything else about your environment that might be a factor? Running on a web farm or cluster or anything like that?
It works fine for me and I would think if there were a problem there would be more people reporting it.
In addition to the previous places I mentioned where you could set a break point, you could also set one in the Components/EmailMessageTask.cs
You mentioned before that you are using VS Express and had some difficulty stepping through the code. I generally recommend use VS 2010 Pro, you may qualify to get that free via the Microsoft Website Spark program.
Other than stepping through the code everything I know to tell about how to troubleshoot the problem is in the article Email Configuration.
Best,
Joe