Without changing anything at all, I get:

Widget: widget1
Rating: B
  Cost: 0.10
Colors: red, blue, green

Widget: widget2
Rating: S
  Cost: 0.25
Colors: pink, gray, orange

Widget: widget3
Rating: S
  Cost: 0.50
Colors: white
[download]

Maybe your version of XML::Simple is buggy? Maybe you're not running the script you think you are running? Maybe you're not using the XML file you think you are using?