I had the same problem with the overburn option not showing up in Nero – and yes, I set all the expert features as suggested in prior messages in this thread.
To get the overburn option to pop up I had to save a disc image on harddrive (“Create Image” in Nero) and then burn that image to CDR. If I do it that way, Nero doesn’t eject the medium, it just asks if I want to overburn. I say yes and overburn works great!
The window that pops up when you click “Write CD” has a checkbox “Create Image”. Select that and save the image to a harddrive – a .NRG file will be created.
When that is done, click File -> Burn Image. Select the image you just saved and burn it. You should be prompted now with the overburn option.
So far, I’ve overburned on 3 CD-R99s their sizes were 830MB, 810MB, and 780MB. They all work perfectly.
Ordered the CD-R99s from yes-buy.com for $40/100pack. Here’s the URL: http://store.yahoo.com/yesbuy/99min87cdr50.html