I've come up with a simple solution that should apply for all instances of using the same key to pause and unpause. It should also work for any other toggle or toggleable events that you might need.
I've included an image here to show you what it's like: i.imgur.com/NI1oOAJ.jpg
If that image doesn't come through then here's the basics:
1) Create a Global Variable and set it to 0
2) here's the way I input the actions
| System Every Tick
| Keyboard on [Key] pressed
| System [Global Variable] = 0 : Toggles an action, like pause or creating an object etc.
| : Set [Global Variable] to 1
| System Else : un-toggles any previous action, or does a new set of actions.
| : Set [Global Variable] to 0
That's the basic skeleton. The program will check to see if the variable is 0 or not 0 and will take action based on that. It will be a toggle-able event as long as you remember to reset the Global Variable each time.
I hope that's clear enough.
<img src="http://i.imgur.com/NI1oOAJ.jpg" border="0" />