ATC Sound is stuttering badly

[Tenmusicman]

I have searched high and low for an answer to this, so I hope that you can help. I recently had to reformat my hard disc, and since then the ATC sound stutters badly, stopping on single words, such as repeating "Altimeter". It is completely unintelligable. I have checked all the obvious settings, re-installed FSX and my sound card but to no avail. The ATC works perfectly in visual mode. MY sound card is an AudioExcel 6 channel system, and works perfectly with all the other programmes.
Thanks in anticipation.
Tenmusicman

[cianpars]

First guess - soundcard drivers?

IAN