I really don't know what's going on. The media is not bad, even though people will dump on me because it's Ritek 2.4x, the fact I made 46 out of 50 sucessfull burns right from the first disc means it's not bad. I installed the other drive (Samsung SATA) and burned the last Ritek of that batch, same thing. Then I open up another brand name's disc of Ritek's 2.4x (I had no idea they were using Riteks when I bought them) and those are all burning bad too. Single layer 16x and DVD RW 4x seems to burn no problem.
To answer more specifically:
1. First tried Nec ND3550 IDE 16x, removed, now using Samsung SH-S203B SATA 20x drive.
2. Vista Home Basic x64, 4GB Ram
3. Software tried so far- Nero 8.1.1.0, CDBurnerXP, ImgBurn 2.3.2.0
4. Plenty of free HD space, I tried moving source file around to different drive to see if that was problem, no dice.
I tried burning ISOs with all three programs, and data files Nero (haven't tried with CDBurner yet, I've wasted like 10 DL discs, don't want to waste any more).
I'm tempted to do a clean install of Vista at this point if I thought that might help. I was burning fine before. I have no idea what the problem is. I don't know where the problem popped up. It might have been some Windows update that caused the problem. I just don't know.