question about converting 24 bit to 16 bit - SOLVED

This is probably a really stupid question, but here goes:  After I mix down and export a song, I then import it into a track to master.
I put Waves L3 limiter on the master bus, and it gives me the options to convert the bit depth from 24 to 16 and to choose dithering.
 
So here's the stupid question:  If I convert 24 to 16-bit and dither it in Waves L3 in the master bus, when I'm done mastering do I do it again in Sonar when I export the finished song?
 
Greg
 
I was given an article that I just read that answered my question.   Disable Waves L3 dithering and 16 bit depth.