Well despite countless hours of testing it seems a couple of bugs slipped through with the grand exchange system. It actually took several million trades before the exact set of circumstances that caused this problem showed up so you can imagine how obscure it is!
It's nothing too major though, but nonetheless we've temporarily taken the system offline to fix it and get it working perfectly. That's because with a system this important we would rather not risk it. We hope to resume normal operation shortly.
Anyhow the main point of this news post is to reassure everyone that you will NOT lose any items through this. (that's because your items are actually looked after by an older system that has been working fine for years, rather than the new system). Therefore any items currently stuck in the exchange will be retrievable/tradeable as normal as soon as we put it back online again. So no need to worry about that.
Sorry for the inconvenience, we know you're all keen to try out the exchange! Sorry!