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It was indeed on the free version, and I see you are correct. Only the free version was updated to The paid version (at least on the Android Market) is still version 2.1.9. Based upon your question, it appears that the paid version still has the notification sound problem. Hopefully Jona, who reads this forum and saw my original post, and quickly made the correction, will see from our discussion that he now needs to update the paid version as well.
That fixed it! Thanks, Jona. You saw my post, did the programming, and posted the update in just a few minutes. Very impressive!