hey i got a prob i can't seem to solve

my audio is channeled out using HDMI to my lcd monitor, and i've connected 3.5mm audio cable from lcd monitor audio output to my 2.1 speakers.
i get good sound, but the only problem is it has this fading in effect whenever anything with audio starts. and the fading in usually starts a few seconds late. so if let's say i load a game which has an opening movie, the movie will play with no sound at all first, and then after a few seconds, the sound comes fading in from soft, right up to normal volume. so usually i'll miss the first few seconds of audio. it's nothing big but it's getting abit annoying, especially when there's in-game cutscenes and you want to catch the dialogue in the beginning.
same effect happens in the XMB front panel. when i move around my cursor to the different icons slowly, no sound. but when i start moving fast enough, making it generating more sound back to back, then the fading in starts.
any idea how to solve this?
much appreciated