Reports have emerged that following an online firmware update owners of Microsoft's Xbox 360 gaming consoles have been experiencing disc read errors. The updated firmware changed code relating to reading DVD media in order to improve copy protection while also improving storage density to enable games to ship with more data. Since the update has not affected all Xbox 360s, speculation arose that the problem relates to models shipped with a particular brand of DVD drive. Xbox 360s use a variety of brands of the optical drive. Microsoft issued a statement acknowledging the issue, stating that the problem manifests as a 'disk unreadable' or 'disc unsupported' error and that the firm is ;able to detect this issue over Xbox Live.' Microsoft said this ability would be used to 'proactively' contact customers in order to replace the console. Even so the firm advised Xbox 360 owners with the issue to contact Microsoft support at www.xbox.com/support/contact