Appearances (wood grain) rotating for no reason.

When applying a wood appearance to parts I have to apply them to several levels (body, face) to get the correct representation. I think I understand this part and can get the exact picture I want... UNTIL... I save the assembly, close, and re-open it. At random, several faces will most likely have the wood grain appearance rotated incorrectly, different from what I just set it to. This pic shows one such occasion...

I'm on SW2012 SP4.0... using surface mapping type.

I can go and correct all the faces I need but this problem will reoccur. Very frusterating to say the least.

SolidworksPhotoview 360