players to occasionally result in a white screen of death. Version 1.10.05 was released on October 23, 2007. Thai language support was added, while video playback was improved. Adapter charging and startup time were quickened. The prior version, 1.20.02, was released on December 19, 2007. Transferring content via the SD card slot is enabled, though only image files are viewable. Firmware version 1.21.01 was released on February 28, 2008. It improves the player's playback performance of WMA (.wma) files. The latest version, 1.21.03, was released on January 19, 2009, which improves FM radio player operation. Territory variants Units shipped in the EU after a certain date have a different variant of the firmware. The version number is suffixed by the letter "e" e.g. 1.21.01e, 1.21.03e. In the "e" variant, the output level is reduced by approx 6dB i.e. at the maximum setting, 25, the volume is that of the non-"e" variant's setting 20. This is independent of Audio Settings' Restrict Volume. This variant appeared following an EU Commission proposal to address hearing health concerns by requiring a limit on music player output level. The two firmware variants are interchangeable, meaning the a unit's reduced limit may be removed by reprogramming with the non-"e" variant. Undocumented features Recovery Mode > Clean Up restores user settings to factory defaults, something that neither Recovery Mode > Format nor Windows Explorer Format does. AAC Support Creative states that the ZEN supports the AAC audio format. However, only iTunes-encoded files can be played by the player hardware. iTunes's implementation has been licensed by Apple from Dolby and is proprietary. These files are in the .m4a format, which is the same as the Apple Lossless Audio Codec. Creative has acknowledged this issue in a support article. The latest version of Nero-AAC Encoder (1.3.3.0) "solved compatibility issues with some hardware devices", including ZEN. This update makes Nero-Coded AAC files playable on ZEN. ZEN MX The ZEN MX is a derivative of the ZEN launched in 2009. The form factor is similar to the ZEN's, being slightly less than a millimeter thicker at 11.9 mm (0.47 inches). There are a notable feature differences. The ZEN MX does not support .AVI, .MPG, or .AAC files natively. In order for them to be played back on the device, they must be transcoded using the bundled converter. The ZEN MX's button layout is slightly altered, merging the play/pause button with the