It looks like new Xbox 360 DVDs designed to hold an extra gigabyte of data may not work with older consoles. The issue came to light after a user with a 2009 60GB Xbox 360 Pro received an unexpected email from Microsoft warning him his system wouldn’t be capable of playing upcoming retail discs.

“Following a recent update to our system software, we have become aware of an issue preventing a very small number of Xbox 360 owners from playing retail game discs,” reads the email, titled “Xbox 360 Console replacement request” and verified via Xbox Support.

You can probably guess what comes next.

“We have been able to detect this issue over Xbox LIVE and want to replace your console with a new Xbox 360S with 250GB hard drive at no charge to you,” continues the email.

In other words, Merry Xbox-mas!

Standard dual-layer Xbox 360 DVDs can hold up to 6.8 GB of data, but a new format dubbed XGD3 unlocks the disc’s remaining 1 gigabyte of data. Microsoft reportedly trimmed obsolete anti-piracy measures residing in that section of the disc to grab the space back.

The upside of all this, aside from the possibility future content-ballooning 360 games may squeeze onto fewer discs, is that Microsoft’s being preemptive about rectifying incompatibilities before it rolls out its firmware-upgrading system update later this month. According to the email, they’re also sending out codes for one year of Xbox LIVE as well (worth $60).

If you’re tapped with a similar email, it seems the offer’s good through September 30th, 2011.

(via Kotaku)

[Update: Microsoft says the issue has nothing to do with older or newer Xbox 360s. According to Microsoft: