Dont use the tutorial files, go to http://ssorg.bigbird.silverstripe.com/installing-silverstripe/show/253631#post253631 and change your code to use one of the downloadable themes.
By all means go through the tutorials but if like me and your on a mac and you chose the tutorial "blank" install then it won't work (loads of problems for me anyway)
After I stoped using the /tutorial folder, all my errors and blank pages went away.
Good luck