Take a look at what was happening to my lovely new Kindle:
I trawled the web and discovered several forums discussing this type of rebooting problem after buying a Kindle cover...
Well, I had't bought a cover and my Kindle 3 was new out of the box. Only just plugged in using the USB power cable supplied and plugged straight into the wall.
All seemed well, it would turn on and off, I was able to set the Wifi without problems and browse the Amazon store looking for eBooks to read and download.
I even looked at the 'Experimental' browser and was very impressed to see that I cold browse the web.
Then I set it down, having turned it off by flicking the slider to the right. The orange light lit up, and a picture of Darwin's finches showed up on the screen. All looked good until a few moments later when the Kindle started to reboot itself as shown in the video above.
The rebooting cycle was endless, showing the boy beneath the tree and the progress bar. The Kindle progress bar would move to about half way and then pause for a moment, before continuing to the end. Then the Kindle screen would flash a few times and the process start again. Over and over.
The eagle eyed amongst you will notice from the video that the 'fix' to this reboot or resetting problem for the Kindle was to move it away from anything metal... then the cycle is broken and the login prompt appears.
In the video above, the Kindle is shown laying on the metal surface of my Macbook, however as soon as it is moved to a nearby wooden chair, the problem of continuous Kindle reboot stops immediately, and the prompt is displayed.
Other causes of the reboot:
I think that some covers for the Kindle may also cause the Kindle to reboot non-stop as the cover may have metal parts, and the proximity of the metal to the Kindle itself is enough for interference with the electric field around the device to the point that it starts to re-cycle or reset continuously as shown above.
If you have this problem with your Kindle, try:
1. Removing covers with metal parts (this includes retaining clips that engage with the sides of the Kindle)
2. Placing the Kindle away from other metal or electrical contact.
Once the Kindle is well away from anything metallic, the re-booting should stop immediately!
Let me know it this has helped you, I look forward to hearing your thoughts!