You've heard about cracking open a book, but how about cracking open a Kindle?

Apparently this is happening to some owners of Amazon.com's electronic book who also bought the optional, $30 protective cover, including one unhappy gadget lover who filed a federal lawsuit today in Seattle.

Matthew Geise, executive director of a Seattle property management firm, bought a $359 Kindle 2 in February for his wife's birthday, plus one of the official Amazon Kindle covers.

After about three months the Kindle started cracking around the points where the cover attaches with metal clips. The cracks grew and on July 6 the screen froze and the device (shown above) stopped working, according to the class action complaint that seeks refunds, treble damages and legal costs.

"I was just looking at it and thinking, those cracks are growing and growing,'' Geise said in a phone interview.

Several Amazon representatives did not respond to repeated calls and e-mails seeking comment. They shouldn't be surprised. A number of customers have posted complaints at Amazon.com, in reviews of the Kindle cover.

"Like a lot of other reviews, the faceplate on my Kindle is cracked from the upper clasp. I don't know if this happened when I put the Kindle in the cover or if it happened later. I wouldn't have bought the cover if I'd known there was a risk of this happening,'' a reviewer wrote on the site July 3.

A July 13 reviewer with the same problem said "Amazon has been horrible about helping with this issue. I am sorry, but if an accessory is purchased to PROTECT the product, the company should certainly be liable if it is the cause of the damage."

According to the lawsuit, when Geise called Amazon to make a warranty claim on July 7, a customer-service representative said the company would cover the screen freeze but not the cracks, contending they were caused by improperly opening the cover backwards. That damage isn't covered by the warranty, Geise was told, and he would have to pay $200 for the repairs.

A supervisor told Geise's wife, Alisa Brodkowitz, that the cracks are a "common problem" but reiterated that the couple would have to pay $200 to get a replacement unit. The supervisor told them the cracked one may end up being repaired and offered as refurbished, according to the lawsuit.

Brodkowitz insisted she didn't open the cover backward.

The couple's suit, filed in U.S. District Court in Seattle today, said the value of the "matter in controversy" exceeds $5 million. It said the class would include buyers of Kindle 2 and Kindle DX models "installed in a Kindle Cover designed by Amazon."

Geise's attorney, Beth Terrell, said they believe "scores, if not hundreds," of Kindle buyers have had cracking problems. Other consumer-protection class action cases filed by Terrell include suits against Qwest involving Internet fees and against Microsoft and Best Buy over MSN trial subscriptions in Windows Vista.

Terrell said it appears Amazon changed its policy of automatically replacing the cracked Kindles to charging $200 for their replacement.

"They have tried to position themselves as a very consumer-friendly company here in Seattle and around the country,'' she said. "It does not reflect well on their reputation they've spent a lot of time trying to build."

Even if cracks are being caused by people "opening" their Kindle covers from the back side, "there's no warning that's going to crack the Kindle,'' Terrell said.