More info at http://forum.runesofmagic.com/showthread.php?t=204223

Well as RoM forum is extremly slow atm (at least for me) here is official info about maintance: 

1. Dear Runes of Magic Community,

We are undertaking maintenance work today between 18:00h CEST (5pm BST) for one hour which will temporarily affect the trading of gold for diamonds, and vice versa.

We have taken this action in light of the recently increasing number of gold sellers and in order to protect our trustworthy players.

As soon as we’re certain that the trading of diamonds and gold between players can safely resume we’ll lift the temporary block.

Furthermore, those who attempt to trade contrary to our regulations may have their accounts temporarily blocked and the illegal sale of gold through third parties may lead to users being permanently blocked from their accounts and from the game as a whole.

We thank you for your consideration,

Your Runes of Magic Tea ... Read more »