and kept tying until I rendered something always ckeck your file and path names. Note Nicolas Riviera's post really helped me with the path name thing I literally copied it and pasted into textedit changed the HD names the copied and psted into the terminal and it worked.
Check this thread out, I too am a LW Mac user.
Had problems especially with myself trying to come to terms and understanding things.
Also not fully realising that the mac version is still at an early stage so far.