Sound issue Artillery II and III

[seille]

I just runned into a problem with the sounds of artillery II and III and also levelbomber which use the sound of that artillery
for attacks.

I play mostly without sounds and that´s probably why i noticed that so late.
And i do not use art II and III or levelbombers in each game.

These sounds starts to stotter when the combat starts and then after round 10 i get a "echo".

I´m using directX 9.0c and a onboard sound (realtec HD audio)
Modern dual core CPU/2 GB RAM
No problems with the other sounds like artillery I for example.

The difference to the working artillery I that i noticed are different playback rates
and different length of the sounds. Played around with a bit, but all my changes did not help so far.

Are there other guy´s with the same problem ? Any ideas ?

edit: forgot, i runned dxdiag and it showed NO problems.