Audio occasionally working when laptop is connected to TV via HDMI

Hello,
I'm using an HDMI cable to view my laptop on my LCD HD TV. When I'm connecting the cable the picture immediately appears, but I'm having a weird problem with the sound. Sometime it's working, but sometime not! For example, I would try to open an AVI file, and only on the 4th time that I would open this file I would hear the sound (it can also happen at the first time I open it, and any other trials). If it started playing the movie, I would not loose the sound unless the computer goes to standby, and then when it would wake up the sound will be lost. The weird thing is that I'm not changing any settings during the time I'm trying to open the file.

I'm using Windows 7 Ultimate, and I'm tried to view my movie with MPC and WMP, and in both programs I get the same problem. I uninstalled Shark007 Codec pack because I thought it had something to do with it, but the problem remained.

When I'm going to the sound settings I can see that the output it set on the TV and I can even see the green bars changing as the file is playing.

How can I fix this problem? It's a tricky one!

Thanks
Tom

The connector on the computer side or the TV side is broken or dirty. OR the cable is bad.
first try cleaning the cables and connectors with a high quality cleaner made especially for audio video cables.
Then try using a different cable. Hint: if you spend a lot of money on an HDMI cable, you are throwing money away. Cheap cables sold on the internet work just as well as expensive cables.
Also check the SAP settings on the TV audio menu.

Standby is a different problem, unrelated to the cable and connectors, SAP settings. This is a bug in the windows operating system.
We deal with it by turning the standby and hibernate features OFF completely. We leave ON the monitor standby. Then the monitor shuts off, but the PC stays on, and does not corrupt the audio and other functions. Moving the mouse or typing on the keyboard brings the monitor out of standby.