I’ve seen it twice today, once in a news story and once in an e-mail update from a literary magazine. The correct phrase is pore over, not not pour over. This isn’t even marginally debatable as to which is correct, and is another example of people writing what they’ve heard, not what they’ve read. My friend Jody has long had problems training people to write English as it is written, rather than as it’s been heard on television; this is another (minor) example of that.