Yep. Common complaint on YouTube. You have to physically delete the video and upload a new one in order to make it work, and even then, if the checksum or whatever it is is the same, you'll run into the same issue (the new video will still look like the old video in all respects, and be flagged).
Some of my videos in which I deleted and stripped audio to use the YouTube tracks got flagged because they had whatever values were in the previous video I had deleted.
On a side note, you can increase the audio speed by 5% or so, and avoid the copyright. Tested and verified. For most soundtracks, you won't hear the difference, unless you're very familiar with it. Don't recommend doing it though, because YouTube has been extra vigilant in their tracking mechanisms, and have caught a couple of mine a few months later. A temporary solution at best, and could flag your account for deletion, ultimately. YouTube's mechanisms are great on the surface, and prevents unauthorized use, but it's very Nazi in its nature, and doesn't descriminate against legitimate uses (such as parody).