Problem Building header.php to use with $includeHeader

In building a custom header.php, i discovered a problem with my 'include' files. Functions within these included files are not able to access their declared Globals. The variables are available as normal outside the functions, but something about the way miniBB processes the header.php file seems to be destroying them as globals. Any suggestions?

Without seeing the code it's hard to tell... but definitely, all variables must be declared as {$GLOBALS['var']} inside your custom header.