That doesn't happen when I'm reading on the Kindle. The device disappears and I'm lost in the book, which is how it should be.
Librarian Bohyun Kim seems to agree:
The greatest problem I had with an iPad ‘as an e-reader’ was that aside from its weight and the eye-straining screen, I could not really concentrate on reading for a long time. I don’t know if this is a non-issue for others with stronger willpower. But for me, this was certainly a big problem. While reading, I would get easily distracted into web surfing, checking e-mails, and reading tweets and Facebook updates. On the other hand, on this single-purpose device, it was easy to continue reading for a much longer time. Sometimes, I would have an urge to go online and do something else. But often I would just ignore the urge as I simply didn’t feel like moving.