There's loads of threads and posts on here about failed burns or backups not working properly on the 360, and there's 2 common factors.
1. Firmware. The firmware of the burner that is. The ImgBurn log will give you the exact model number of your burner and tell you which firmware you currently have installed. Out of date firmware can lead to coaster after coaster even on decent media sometimes. Look on the manufacturer's website for a firmware update, or Google it. Just make sure you download from a trusted source and make sure that you've downloaded the correct firmware that goes with your burner. Updating the firmware might make no difference at all, but in some cases it will cure all of your burning issues.
2. Crappy media. People don't recommend Verbatims for no reason! They use a high quality dye, the manufacturing quality is excellent, and they're renowned for low error rates and longevity. If cheap discs work for you, that's fine, but often the cause of bad burn after bad burn is the cheap discs you bought cos you wanted to save a bit of money.
Some other things that can affect burns: -
Burn speed. 2.4X isn't always the best speed to burn at. Sometimes it can be the worst. If you don't do test burns at different speeds, you'll never know. There's so many variations of media, burners, and firmware installed on those burners out there, that there isn't such a thing as a universal "best burn speed" that applies to everyone. There are applications that you can use to scan discs for errors, then you can see which burn speed is giving you the fewest. Nero CD-DVD Speed or OPTI Drive Control are two options. I use 8X rated Verbatims and with my drives (Optiarc AD-7200S and AD-7240S), a burn speed of 8X gives the fewest errors.
Third party applications/filter drivers. Some third party apps can affect the quality of burns. Daemon Tools is one such app, in fact ImgBurn will warn you in the log if the SPTD interface (installed alongside Daemon Tools) is installed. Before someone says "but I have Daemon Tools installed and everything works fine", it won't affect every user, but if you've tried everything else and you still can't get a burn that works, it's a possibility.
Old burners. If the most recent firmware of your burner is years old and the company no longer supports it, it may not work well with the latest media. Burners are cheap, so the solution is to get yourself a nice new drive and your problems should be solved!
That covers most of the reasons why burns will fail. Hopefully someone will find this useful.
