You are not alone
A lot of people will be seeing this happen to low budget CD-R's they bought in the past 4-5 years. And don't forget most of these brands gave you a 20-30 years warrenty...
Have a look here:
CD-R Quality
A good rule is NEVER to buy CD or DVD recordable media which is made in Taiwan... To my knowledge all
Acer media is from Taiwan...