Not really a bug, but definitely a glitch.
You end up with a url string something like /data/person/123?id=123 which is not very desirable.

I have worked around this by overriding buildUrl in a class derived from Ext.data.proxy.Rest and doing the following:
Code:
if (request.params['id'])
            delete request.params['id'];
To be fair I'm still using PR3.

Edit: oops, I meant to post this in the 2.x bugs forum. How do I shift it?