Need Help

Gibberish from setup.php

Weird installation problem

I unzipped yacs at a hosting provider (PHP5 and MySQL 4), and the first time I access setup.php I get this: UM6^... (and a lot of question marks).

I get similar gibberish from other php files. I narrowed it down to those file that include 'shared/global.php', if I comment that single line the gibberish disappears.

What could be the problem?