Amazon.com has been sued by a user of its Kindle electronic reader who claims the device's cover, can break the screen and make the device inoperable.

The case which has opened in the US District Court for the Western District of Washington, claims the covers designed and sold by Amazon to protect the device often end up cracking the Kindle screens due to pressure on the hinge.

An Amazon spokesman said that "anyone who has an issue with the cover attachment mechanism to return the cover and device for a free replacement so we can investigate further."

Matthew Geise, wants a class action to represent all owners of a Kindle 2 or Kindle DX installed in a Kindle cover designed by Amazon. Geise bought the cover for his wife on Valentine's Day 2009 and her Kindle 2 began to crack three months after purchase.

A customer service supervisor at Amazon acknowledged that such cracking was a "common problem" but would not be covered by a warranty.