I discovered today that the technique text ";Marimba, high, M187 mallets"; was triggering marimba rolls where I only notated normal strokes. Unchecking Sibelius's ";play on pass"; box returned the strokes to normal as desired.

Not quite sure what is going on here, especially considering the text ";Marimba, low, M182 mallets"; doesn't do anything unexpected, but I thought it might be useful information. This was with the Marimba Medium LITE instrument.

Good catch, Joe!

The reason it does this is because the ";high"; text is defined for use in the Cymbal Rack Combo to trigger the high cymbals, which have a Mod Wheel value of 89-127, resulting in the rolls on marimba. The ";low"; text doesn't do anything because ";low"; leaves the mod wheel at 0. I haven't tested it, but the ";medium"; text would trigger either dead strokes or birch shafts --  not sure off hand what the mod wheel value is for that text.

Good find!