I can't find the topic that talks about the "correct" way to burn backups. It had some info on what media to use, what burn speed, and some program that could check how well the burn worked. I searched the topics but I can't seem to find it.
Verbatim discs tend to work best, burn between 4x-8x ( can vary a bit depending on your burner )
Also, use "ImgBurn" the best program to burn Wii games, as well as other stuff (IMO)
if you want, you can "Verify" the disc after burning within the program, and if it pass that,
it will probably work flawless.