Character Encoding & Boost

I started playing with Boost to try and speed up Drupal.
While I haven't enabled the page caching to work nicely with theme switching yet, I did notice that Boost totally nailed the character encoding.

I was wondering if this is a Boost issue, a J-helper issue or whether there is a simple trick to get around it.
I'll probably be looking at this, so if I get an answer first I'll come back with it.