In the SPD-SX there is a feature called "Pad Control" which allows you to control various parameters by hitting the pads. If you're hitting a pad on the SPD-SX and it's changing your kits, this means that pad has been assigned to change kits within the Pad Control Menu. If you don't want this to occur, disable the assignment with the steps below and that should take care of the problem.
Here's how:
1. Press MENU.
2. Cursor to "SYS" and then press ENTER.
3. Cursor to "PAD/FS CTRL" and press ENTER.
4. Hit the pad that's changing the kit, and then press the (-) button to select "OFF" for that pad. Repeat this for any other pads if needed .
5. Press EXIT when you're finished. The new setting is saved automatically.