Regression: Sound broken in PoP series

[M.Kiesel]

Hi!

The following commit breaks sound in (at least) Prince of Persia SoT and 
PoP TWW. Reece, let me know how I can help with that.

commit ce06de420874b9983324508f8257a580fee341ca
Author: Reece Dunn 
Date:   Mon Dec 22 13:33:43 2008 +0000
     dsound: Correct the dsound fraglen calculations.

Regards