Another think:
Checkin validation of feed at Feed Validator this is the result:

This feed is valid, but interoperability with the widest range of feed readers could be improved by implementing the following recommendations.
  • line 23, column 0: description should not contain onmouseover attribute [help]
    <input type="hidden" name="cart_quantity" value="1" /><input type="hidden" n ...
  • line 23, column 0: description should not contain onmouseout attribute [help]
    <input type="hidden" name="cart_quantity" value="1" /><input type="hidden" n ...
  • line 36, column 2: Missing atom:link with rel="self" [help]
    </channel>
    ^