No, doesn't have to face a certain way. The blade will spin in the blade holder, which allows it to cut different directions.
A dull blade could be the culprit - do you have any other blades? Even a 45 degree would work well for cardstock. Make sure you are using the CD method to set your blade height - found in the learning center. If you are getting drag marks, lift the blade up just little. If that doesn't work, it may be worth a shot to watch the webinar (8/2/11) that goes through cutting materials and different things that I do that helps me troubleshoot.
http://blackcatus.com/learn/?page_id=228 The first 26 minutes talks about cleaning the pinch wheels, which likely isn't the problem. I hope that helps get you pointed in the right direction. Keep us posted.