As HD-DVD continues to grow, so it seems do the firmware updates.
The Toshiba.com website has made Firmware Update V2.0 available via their website. It is applicable to the following models: HD-XA1, HD-A1 and HD D-1.
According to the site, "This firmware update adds support for certain anticipated network delivered content in future HD DVD discs, improves certain video and audio processing capabilities, as well as addresses certain disc playback and HDMI/DVI related problems identified by Toshiba."
Included at the site is information on how to obtain the update as well as an FAQ list.