SP2 Integration into SP1 to burn

I have followed the instructions on how to integrate SP2 into SP1 to the letter. The integration was a complete success. However where the instructions say I can burn the contents of the integrated directory to CD-R, I find that the directory size is 727MB. Tried to burn this anyway with Nero, and as I know the capacity of a CD-R is 703MB, it refused telling me that the compilation is 718MB which is still bigger than that of a normal CD-R. What am I doing wrong?