Check them in another PC...if they work then why go to the expense of buying and burning new disks? Welcome to the forum If you do a search on +/- compatibility using the forum search-engine you will turn up as much info as you need on the topic. However, like I wrote above, if you can read the disks okay in another PC don't go to any further expense...
P.S. I think Geno is right...your drive may indeed be a dual format unit and you don't realise it. It's quite rare these days to come across a single format unit, if at all.