Filament extrudes at an angle
I've personally had this happen when I had a minor clog in my nozzle. 

My first steps to fix this would be:


Make sure the exterior of your nozzle is clean. I've had bits of plastic pull at the extruding filament and change it's direction.
Attempt a "cold pull" or "atomic pull". On my Replicator 2 I do this by removing the extruder motor, heating up the hot end, manually pushing a length of filament through the nozzle, letting it cool slightly and tugging the filament (and hopefully the clog) out of the nozzle.