Hardback book warping

Has anybody else noticed their hardback RPG books' covers are warped? I got both the Monsternomicon and GURPS WWII recently, and both are warped. The GURPS book is warped more than the Monsternomicon.

Has anybody else noticed this problem, or am I just weird?

Also, is there a solution other than bunging them under my massive pile of books and hoping that the pressure is enough to turn the carboniferous coal of their warpage into the brilliant diamonds of straightness?

TWK

My Spells and Spellcraft is a little warped but my Monsternomicon is fine. Large weights help flaten them out as well.

I think it's the result of them being stored in damp places. Sometimes the pages also go wavy, or 'wobbly' as the phenomenon was affectionally termed by the folks here...

Call of Cthulhu d20 was famous for the wobble, and some copies of Godlike had warped covers. I thinks stuffing them in a shelf stuffed full with other hardbacks would help alleviate the problem, even if getting them out after a while might pose an entirely new and different problem.