Anyone have this problem?

I'll be doing my normal routine and stopping my toons from running off edges when all of a sudden the game freezes a second and then my toons are stuck in overdrive. 'Stop' effectively holds them in place but as soon as I release it (to do anything else) they start running again. It's as if the system pause caused a key to flip on inside the game that won't turn off until I reload the UI, forcing them to stop.