Seems you have two topics regarding the same issue. Check disc failure is a sure sign of a failing drive. I don't believe you are burning the image properly. Check your other post for the link to a diagnostics test for your hard drive. As stated, if your hdd manufacturer doesn't have a tool then use Seatools. Use ImgBurn as stated in the answer above. I never heard of Sonic being able to burn ISO images. I may be wrong though.
Edit: Apparently Sonic does have iso image burning capabilities. I would still use ImgBurn however. Somewhere something isn't being done properly with Sonic. Otherwise you would be able to boot from the disc.
Edit #2: I visited the link in your other post for the Ftool. You cannot use that image on a cd disc. It is specifically for a floppy. The reason it't not offered in an iso for cd disc is probably related to the age of the tool. It was created for windows me - Xp. With all due respect, make this easy on yourself and those helping you or attempting to help. Download the Seatools DOS iso and ImgBurn. Burn the iso to a disc and boot. Choose the long test not the short test. If there is a chance of repairing the bad sectors you fair better with the long test. Even if your hdd passes the test, which I hope it does, Seatools is a handy little tool to have around.