When I simply press (not hold) Super I always see the shortcuts list. And after I release the button it stays on my screen. Normally pressing Super leads to Dash opening and to view the shortcuts list I need to hold Super. So to open the Dash I need press Super twice. I have ThinkPad T520i. I tried to disable shortcut list, but it didn't solve the problem.
For reference, the Sticky Keys option is in the Typing tab of Universal Access in System Settings.