Basically they closed business because of big losses and has declared bankruptcy, read more at their startpage: http://planetaxel.com/
This is really sad, as they were my primary site for US material. Has one item that they cancelled now (Apocalypse Now Bluray), will see what happens with my refund.
Bought my first item from them in 2006 (first season of Veronica Mars), had a Helium VIP Pass Platinum when that was available, and probably bought around 200 items from them (had five pages of order history).