There may be a lot of things -
- You are burning too fast. Compressed files are very fragile, one byte is lost and whole decompression would have problem. So try to burn at a slow speed.
- Also I have seen this happen if your hard disk has some file system error. File burns okay, but since file was read in a wrong way from hard disk, the burned file is corrupted. So do a chkdsk
on your hard disks regularly or before you burn.
- Use WinRAR which has an option of saving recovery data in the compressed files. This increases the size of the file a little, but in case of corruption you have a chance of recovering from these errors.
- Some people also advise to create an ISO image and then burn the ISO image to disk, rather than just burning files straight to the cd/dvd. This reduces data loss problem during burning process (as they say).
Well other remote possibilities I can think of are malfunctioning CD/DVD writer, low quality disks and cabling problems