Nero CD Speed, c1 and c2 errors?

I used to run the CD speed on the older versions and it looked totally different. I got the new version of nero and now when I run the CD Quality Test on almost any CD that I have, it says it has C1 and C2 errors (even though it doesnt draw any C1 or C2 errors on the graph… it shows some in the list below the graph).
I just burned a Fuji Taiyo Yuden at 16x and this is what I get:

C1 errors
-tot: 23923

C2 errors

what do these numbers mean? I dont get it. My CDs seem to work fine, why does it say that they have errors?

anyone? just some short explanation would do :bigsmile: