The disc reading errors currently being reported by some Xbox 360 owners is "not specific to older or newer versions of Xbox 360", according to Microsoft.
Yesterday the company began to offer replacement consoles to users affected by the error messages, as a result of a recent firmware update. This was assumed at the time to be an incompatibility with certain models of DVD drive.
However, Microsoft has released the following statement:
"Following a recent update to our system software, we have become aware of an issue that is preventing a very small number of Xbox 360 owners from playing retail game discs. This issue manifests itself as a unique 'disc unreadable' or 'disc unsupported' error on the screen and is unrelated to our recent public beta.
We are also able to detect this issue over Xbox Live and are proactively reaching out to customers that may be impacted to replace their console. Any Xbox 360 owners receiving this error are encouraged to contact us at www.xbox.com/support/contact so we can verify if the console has been impacted.
"This disc read error message is tied to a change in the disc reading algorithms in a recent software update and is not specific to older or newer versions of Xbox 360."
It is still unclear what issues are dictating when a hardware replacement becomes necessary, but Microsoft has previously indicated that the numbers affected are "very small".