In reference to this thread http://www.hotukdeals.com/deals/toshiba-regza-32xv635-full-hd-100hz/708682#comments
I would like to point out that I too have been suffering from audio distortion while playing my Xbox 360 through HDMI. This only happens after playing for a good few hours but none the less I still called Toshiba in response to an update on their website firmware news: http://www.toshiba-om.net/firmware_hdmi_issue.php
My TV is the 37XV635DB and what Toshiba are doing is sending out memory sticks with a firmware patch update on them. Tim today said I 'should have the stick within a few days time'
Please call this number if you are effected - 01932 841600 and ask for Customer Services (television)
I also asked if this was rectifying the problems and he assured me this will definitely sort the issue....fingers crossed :)