Category permalinks

I’m not sure if this is a WP3.0 issue or not, but I have made my post permalink structure this:

/0/%postname%/

I did this because I learned that it is better to start a post with a number, and before I just had /%postname%/.

What this is doing though is starting off category pages with /0/category/ instead of /category/. Is this the way it is supposed to work or is this a bug?

Thanks!