yay I fixed the Byte Order Mark! (still getting a blank page at checkout but I will go through the Debug and check that out.
For anyone else having this problem... the problem can be in one of these locations: NOTE!! This is for those who are using other languages that require utf-8 encoding... if you arent then these setting could cause other problems

includes/languages/english.php
admin/includes/languages/english.php
includes/classes/db/mysql/query_factory.php

If you have not correctly set the utf-8 encoding in these pages you will in fact get a BOM.

Other problem spot can be in the Database itself... use phpAdmin and ensure that your MySQL connection collation is set to utf8_general_ci

That should clear up your BOM mark error and then you can go on to fixing other problems