I do regular backups with Norton of my files onto a DVD+R disc. I have never had a problem until today when it said that the new disc wasn't seated in the drive, so it was not recognized,etc. but it was. So the backup couldn't be done.
More aboutdoesn recognize disc drive
Did you change brands of discs? Is the drive working fine with other discs?
Sometimes older drives don't recognise DVD 'R's (only DVDs) Have you used this same drive to do this before ?