I have a 750 and a 320. Both are over a wireless network using MediaLounge on a XP computer. Pictures and music work great on both. My movies work fine on the 320 but will not play on the 750 over network. they will play if I load them on a USB drive. It will show my video library but as soon as I hit OK or Play the TV screen goes black, not even getting the "thinking circle" thingy. I am hooked to the TV using composite cable and using the latest firmware, hooked to a Sharp Aquos 60" LED. I purchased this 750 about 3 months ago over eBay and it worked fine when I got it, just noticed the .avi problem about a week ago. Have tried all the resolution settings with no luck. Like I mentioned earlier, 320 plays fine and the movies will play on the 750 of the USB, just not off network. Thanks for any help with this.