TS2010 Steam sound problem

[ilovenxstage]

I've downloaded a couple steam engines from the Trainz download station, L&N 152 and SP 2479. I also downloaded the Steam Soundz package. The new sounds are great, however I only get two chuffs per wheel revolution instead of the proper four (two cylinder engines). How might I go about correcting this? I have a number of other steam engines that have the correct four chuffs (or eight for simple articulateds).