Atom feed error: ‘obsolete namespace’

My RSS2 feed validated fine, but my attempt to validate the Atom feed turned up multiple errors. The first one reads “This feed uses an obsolete namespace” followed by the following:

&lt?xml version=”1.0″ encoding=”UTF-8″?&gt&ltfeed version=”0.3″

There’s a little red caret under the &lt before ‘feed’

I’m very new to this, and I’d appreciate if someone could please tell me how to fix this, I’d appreciate it.

Thanks in advance.