Instruct: Classify the given review into positive or negative sentiment.
Query: Paper curls

I had a Brother 9600 printer. So when it broke, I bought the 8840D expecting the same features and satisfaction as the 9600. Since my office isn't air conditioned, I expected some slight curling as was the case with the 9600 but the 8840D was so much worse. Even 24lb laser paper wouldn't print more than a few copies without backing up. If you can stand the long wait, customer service is good. They sent a replacement drum and when that didn't work another printer. Neither stopped or reduced the curling to a tolerable level. I regret having to return this printer since it has so many other good qualities.