I just noticed a bug with $MetaTags (or with the code to call it)...MetaTags expects a boolean $includeTitle to tell it whether to print the <title> tag.
The problem is, if you do $MetaTags(false) (or $MetaTags(true)) the argument gets passed as a string, rather than a boolean. Which means it always prints the title, even if you pass in false.
I've modified MetaTags to check for the string 'true' instead of boolean true, but it might be better to make the templating return a boolean.