I've tried 3 different disks so far and each 1 is the same.
Are you using the correct format?
The main thing to remember is to get discs that are of the same format as your DVD drive. For example, if you have a DVD drive that records in the DVD+R/+RW format make sure you buy discs that have that label on the packaging. You cannot use a +R disc in a -R recorder or vice versa. However, many DVD recorders now record in both the - and + formats.
You say you have used 3 different discs but have you tried a different make? My advice, when it comes to blank DVDs, stick with major brands.