I'm having a similar problem with my VGN-FW235D running Windows Vista 64-bit. In the past plugging in the HDMI cable automatically switched audio from the onboard laptop speakers to the Pioneer Elite Plasma TV -then one day for no apparent reason I could not get HDMI audio output to my TV. Like you I manually switched the playback device to HDMI and observe the left and right audio level bars rising and falling with an audio signal, but no output from the TV. After searching the internet endlessly and trying every so called solution without success, I eventually discovered after much trial and error that I can get an audio output on the HDMI by rebooting my computer after manually selecting the HDMI as the "default" device. To get audio back to my laptop speakers I must then reverse the process setting the "default" device back to my laptop audio and rebooting again ...... this works but is obviousely very inconvenient and time consuming. Although my Vaio is getting on in years, it has proved to be the best laptop I have ever owned ...... sure would be nice to have this problem resolved in a simpler way. Not sure if this will help you ftcsony, but it's something you could try.