[hero]

Its because some of the Prs names differ from sound mod to sound mod....ie....in SFX.08 the merlins run under "motor.Merlin.prs" , in the UI 1.1 they run under "motor.Rolls-Royce-Merlin.prs" , so anyone who, for example has made a sound set for the UI 1.1 will have to change the Prs header to suit the older sound mod otherwise the sounds wont work or in some cases the game will just crash, its a pain I know but thats modding.....

EDIT....However I could be barkin up the wrong tree , as I havent downloaded it to have a look.

Jafa.