Apple has reportedly suspended sales at its retail stores of iPhone cases that slide over the devices glass back. The company is apparently concerned the cases could cause scratches and cracks in the iPhone’s glass.

[ad#Google Adsense 300×250 in story]According to a report on Cult of Mac, concerns of trapped dirt led to the decision to ban sales of the products at its stores. The glass on the back of the iPhone is not made out of the same tough material that’s found on the front of the device.

The snap-on cases are apparently not affected by this issue, according to the report.

Some of the products affected are even certified by Apple’s “Made for iPhone” program, but are currently unavailable from Apple.

Commenting on the Mophie Juice Pack Air for iPhone 4, Ross Howe, Mophie’s vice president of marketing and new business development, said the product is available from the company’s website and AT&T stores.

Tim Hickman, CEO of Hard Candy Cases, said there is no issue and that it’s “a perception problem, not a real problem.”