I've recently connected an EeeBox 1501 to my LCD TV in order to utilize the computer as an HTPC.
If I switch off the TV or just change the input source, after turning on the TV back on or switch back to the PC's HDMI input, there's no picture.
The computer runs Windows 7. My previous HTPC, an Acer Aspire iDea 500 had no such problems running first Windows XP, and later Vista.
The PC runs fine and outputs sound all the time.