Are you using the Sibelius 5.2 template, have the correct soundset loaded, and are looking at the keymaps in the manual to make sure you're in the right octave? Sometimes you have to hit the octave +/- keys on your keyboard to play the right notes.
Legacy Forum Post
almost 15 years ago
This sounds like an issue that some people have experienced when trying to use the marching bass drum sounds found within Sibelius Sounds Essentials. While these are derived from VDL sounds, they may not behave the same since they're not a Tapspace product.
As J Mattson suggested, be sure you're using the VDL/Sibelius 5.2 template, have properly assigned the 5.2 template sound set, and are writing your music into an instrument (staff) that comes from the VDL family of instruments. If you're using the stock ";marching bass drums"; instrument (stock within Sibelius), it won't function properly.