bill - 2:19 am on Feb 9, 2010 (gmt 0)
The problem is that only Firefox, Opera and Safari have this option to subscribe to feeds in the URL bar. IE provides a separate button in a separate toolbar, and Chrome doesn't appear to have anything at all (unless you add extensions). In my experience feeds show up in the order that they are listed in your <head>. Simply changing the order of the <link>s to your feeds should fix things for you.
Another option would be to set only one feed in the <head> and then there will only be one option. Then if you have other feeds you could provide alternate links to those on the page somewhere.