Blizzard has publicly apologised for Diablo III’s server problems, admitting that it didn’t prepare thoroughly enough for the game’s launch.

"Despite very aggressive projections, our preparations for the launch of the game did not go far enough," said Blizzard via Diablo III's Battle.net forum.

As well as hampering players’ ability to get into the game, server problems have now delayed the launch of the game’s auction house.

"In order to make sure everything is continuing to run as it should, we've decided to move out our target launch for the real-money auction house beyond our original estimated date of May 22," said Blizzard.

UPDATE:

Blizzard has announced that the real-money auction house will launch May 30th.

Original story:

"We're continuing to monitor performance globally and will be taking further measures as needed to ensure a positive experience for everyone. This includes some maintenance to implement additional improvements for each region."

It's also looking into issues with the achievement system.

"We sincerely regret that your crusade to bring down the Lord of Terror was thwarted not by mobs of demons, but by mortal infrastructure."

“Thank you again for your patience while we reinforce the gates of Sanctuary and further strengthen it for your onslaught,” the post concluded.