Feb 1, 2011 14:00 GMT  ·  By

Call of Duty: Black Ops has just received its first piece of downloadable content, in the form of the First Strike Map Pack, but issues are already popping up, according to reports from Ubisoft.

Call of Duty: Black Ops has broken sales records since it was released last November, and is aiming to increase its profit margin even more with the release of the First Strike map pack as a timed exclusive for the Xbox 360.

After plenty of teaser videos released by its development studio, Treyarch, the map pack has finally been launched on Xbox Live and can be downloaded by users of the online service.

Sadly for hardcore Call of Duty players awaited the DLC, it seems that issues are already popping up, as Xbox Live can barely cope with the huge demand.

According to Microsoft's Xbox Live status page, the service is in alert, "Users may be unable to purchase the following DLC for Call of Duty Black Ops: First Strike: Pack 1 when using the Xbox 360 console. This content is available in the COD Black Ops in game store and from Xbox.com."

Instead of actually visiting the Xbox Live Marketplace from your console, Microsoft is advising players to either use the Xbox.com web portal or purchase the First Strike DLC straight from within Call of Duty: Black Ops' in-game store.

These are the best alternatives, seeing as how the map pack weighs in at a hefty 646.37 MB, which will be downloaded quite slowly depending on the stress of Xbox Live servers.

The First Strike Map Pack is online since 9am ET, 6am PT and 14:00 GMT all over the world.

"First Strike contains 5 incredibly diverse maps spanning the globe; featuring 4 multiplayer maps and a new Zombie experience. Includes "Berlin Wall", allowing combat on both sides of the imposing wall; "Discovery", a desolate, frozen German outpost in the Arctic; "Kowloon", battle in the rain along the rooftops of a towering Chinese sprawl; "Stadium", an intense locale with a pro hockey arena backdrop; and "Ascension", where you fight zombies in a Soviet launch facility," revealed Treyarch in a statement.

The First Strike DLC map pack for Call of Duty: Black Ops is available for 1200 MS Points or $15.