Why should they buy back shares?

Typically, you do that when you believe it's a better investment than doing something else with your money. Do you think it's a good investment? :>):>):>)

Besides, contrary to what some might think on this board, they're not exactly flush with cash. IF their plans for "whatever it is" comes to fruition, they'll need capital. Don't forget legal costs which may prove to be significant. Lots of better things to do with the cash.