Could someone give me a run down on what exactly booktype means. When I changed my firmware I had option to change my booktype. I don’t think I quite understand that part. Also how much of a difference dose media code make on DVD’s I bought TDK with CMC code. Is one code better than other??
Thanks
Increased compatibility: DVD bitsetting - Explanation 
About the media code: this code indicates the real manufacturer of your media. If you bought TDK media with media code from CMC it means that CMC is the actual manufacturer of your TDK media. So, each media only has one media code as this stands for the original manufacturer. TDK is just the brandname which you shouldn’t confuse with media code! Hope this explains it
No reference to nec in post, but will assume that you need info about them. Check out this post http://club.cdfreaks.com/showthread.php?t=120934 This will give you all the basics about nec burners.
For the short of it, booktype = play back. If you don’t use booktype you will find a lot of problems with playback of + media like not playing back in most tv top players. Also Ritek, TY, RICOH are some of the better ones and if you want to read your B/U’s in the future stick with good media. 
Look around the forum for a list of good media to go with your burner.