[Guest]

Its strange, all Spits use motor.Rolls-Royce-Merlin.prs.
The buttons file assigns the prs to engine,therefore there are different version buttons files for each soundmod version. I had problems when I accientally installed the 0.90 buttons file for my 0.93 install. Maybe, try the 0.93 soundmod if reinstall doesnt helps.
edit: Check for duplicated buttons file first!

Thank you for the answer.
The button file affects sound?

What should I reinstall?