Hi there and sorry for posting this in the Computer section, I just didn't find another one that seemed appropriate enough for this.

I have a seemingly quite unusual problem with the sound when I want to play on my Xbox360, which is connected via an HDMI cable to my Amilo LXL 3220w LCD monitor.
The problem surfaces whenever there has not been any sound for a few seconds.

For example, usually, when you move between menus in the Xbox menu there is sound whenever you move. In my case, if I haven't touched a button in the last 5-10 seconds, then there will be no sound at first. The sound slowly starts building up until it's normal after about 4-5 seconds, hearable only after 3 seconds.

In games, this is most commonly a problem when a video sequence starts. I cannot hear the first few seconds of any sequence, afterwards it is completely normal as usual, though.

This problem does not occur when I play on my TV and does not occur when I use the Monitor with my PC. I also tried to search for help via Google, have only found a single person with the same problem so far, though, who also did not have a solution. [In his case it was with an Asus monitor, though.]

I would be very grateful if someone of the extraordinarily competent MMO-champion userbase could help me find out where the problem lies and how one can solve it.