Gearbox’s designer Matthew Armstrong has clarified why the second piece of downloadable content for Borderlands, Mad Moxxi’s Underdome Riot, is arriving over a week later PlayStation Network than it will on Xbox Live — the PS3 version just needs a little more time in the oven.

“We try to get everything out to our fans as quickly as possible. Development, testing, certification, and a multitude of other factors all contribute to defining the release of DLC or games on various consoles,” Armstrong said in a recent chat. “When we find that the release/ship dates for different consoles do not fall on the same date, we have to ask ourselves whether it’s better to delay some so they all ship at the same time or to allow them to ship when they are ready, regardless of the other versions.”

“On Borderlands, we’ve generally decided to release things when they are ready to be released. Almost every developer or publisher has to make this call sometimes. It is inherent to making games. Next time maybe we’d love to do things differently.”

Mad Moxxi’s Underdome Riot will hit XBL tomorrow, December 29, for 800 MS Points and PSN next Thursday, on January 7, for $10.