I have had one book out of more than 150 crash my t1 and it wouldn't open on my 350. I have read over 600 books on my various Sonys so I don't think it is a common problem I don't expect it to read broken books.
I just said oh well and didn't read it.
But if it wouldn't read any/most of my books I would take it back. And of course if it didn't read the only book I wanted to read I would take it back.
Lucky for me I don't have to as I like it
Helen