Do I need an updated LDraw folder?

[Scott Classen]

I just downloaded and am playing around with Bricksmith (a great program BTW!). I'm having loads of fun. My 6 year old is bringing me his MOCs and together we are making little instruction booklets to give to his school buddies. We are having problems finding some wheel parts and I'm wondering if the LDraw folder that came with Bricksmith is outdated. How can I tell if my parts list is the most up-to-date? I am also a bit confused about how to update or add new parts. It seems I would need to run some EXE program which is entirely foreign to my Mac sensibilities. I see an lcad1101.zip file that was released today. Does this contain only new parts or ALL parts? If it contains only new parts, how do I merge them into my existing LDraw folder?
Thanks