Wow I just added a ctrl+shift+s shortcut in preferences like you said and it works! Thanks a lot!

@mazurek said: ...I did not find any option to force this on sketchup... you can't over-ride System commands, you need a plugin to save as different version and use a different shortcut key. have you looked at this one... http://sketchucation.com/forums/viewtopic.php?p=294768#p294768 john

yup, it's just a port of the VRayMtl from V-Ray for 3D Studio Max

I agree, check to see if there are duplicate objects fighting for the same space. It is also good practice to model with front faces out. I don't think having a back face out would cause this, but it is good modeling practice to eliminate these back faces.