MonoDevelop AutoComplete is using the wrong hotkey?

Does anyone know why my Spacebar is now acting just like my Tab key for autocompletion? Generally, I would have to press Tab to accept the auto-complete suggestion, which has been great. All of a sudden though, Monodevelop has been accepting my Space key as an alternative autocomplete hotkey! I can’t for the life of me figure out how to stop it doing that!

It’s always been that way - you’re just now noticing. Other characters work too. (.)