Strange XML Parse Error

Hi there,

I created a basic blog app using ./script/generate scaffold command,
everything works fine, however, when I try to get the xml of the posts
like 0.0.0.0:3000/posts.xml, it gave me a:

XML Parsing Error: XML declaration not well-formed
<?xml version="***" encoding="******"?>

I didn't touch any of the scaffolding code. Am I missing some default
Gems? I'm running Ubuntu 9. I didn't have this problem on the Mac.

Any help is appreciated.