The problem you're probably running into is lyrics being PD, but arrangements being copywritten. You'll probably run into the same problem with "Sloop John B" and a few others.

Unfortunately, there may not be much you can do with a webhost. The best I can think of is for you to find some reputable source (BMI may be of help) that lists the lyrics as "traditional", and have your arrangement be something obviously different than the copywritten one.

Of course, someone else out in 'cat land will probably have better ideas... I'm just giving opinion.

M