Microsoft has blamed the foul-up that led to hours of misery for Modern Warfare 2 fans on a "process failure" during deployment of the Stimulus Package DLC and its associated Title Update (patch).
"Through a process failure on our part, the Modern Warfare 2 Stimulus Package was released [on 30th March] before the Title Update (TU) for MW2 was available," Operations Manager Eric Neustadter wrote on the Xbox Live Operations Blog.
Accidentally releasing the DLC before the patch required to play it presented a big headache for Microsoft's Xbox Live team.
"For a couple of hours the result was unpredictable but most people couldn't get into a game through matchmaking," Neustadter explained. "In technical terms, it was a big hairball that we had to unwind."
Once the patch and DLC were unwound and spooled out correctly, the team still faced issues regarding POSA - "Point of Sale Activation" - cards, which you buy at a shop and the shop then activates for you at the checkout. Neustadter didn't say whether the DLC rollout and POSA issues were related, but suggested that perhaps they weren't. "The Stimulus Package has been so popular that our POSA vendors that make those magic point cards work are a little backed up," he wrote.
The Stimulus Package palaver will undoubtedly sting for Microsoft given that the platform holder made such a big song and dance of buying an exclusivity period for Xbox 360 owners.
Microsoft has previously told Eurogamer that its exclusivity deal lasts 30 days, after which we can presumably expect to see the Stimulus Package rolled out on PC and PS3.