40125s has errors at 40x?

I just installed the drive and attempted to burn some Ghost images. I am using Nero 5.5.9 and I believe I have smart burn activated. Anyway, at 40x Nero came back and said “successful” (I had run the drive speed beforehand), but when I had Ghost check the image integrity it couldn’t read the cd. I am using Taiyo Yuden CDRs although I don’t know the speed they are rated for. I subsequently burned the image at 16x and the image is not corrupted.
Does anyone know whether this is more likely a media issue or has my burner got problems. I am pretty new to all of this so apologies if my questions seem a little basic. :eek:

I checked the disks I am using:

Disc Type, Material = CD-R, Cyanine
ATIP Lead-in = 97m 24s 01f
Norminal Capacity = 702.83MB (79m 59s 73f)
Disc Manufacturer maybe = Taiyoyuden,DX Dye
SMART-BURN Speed Limit = 40X

Therefore, the Ghost images should have worked. The drive has the R40ZS0N firmware loaded. Does anyone have any ideas why it didn’t?

I guess Smart burn doesn’t really work?