How do I use Load/Save for a simple Undo?

I thought this one would be easy. It's so straightforward I don't know why it's not working. The AI hasn't been helpful this time so I turn, once again, to the geniuses here in the forum!

Just to get the basics of my one level Undo working I added:

+ Keyboard: On Space pressed

-> System: Save game to slot "undo1"

-> System: Create object fam_cards

+ Keyboard: On Z pressed

+ Keyboard: Ctrl is down

-> System: Load game from slot "undo1"

Why doesn't this work? I press space to create a sprite, then press CTRL+Z and the sprite is still there.

Let's see the actual event sheet, and also is it actually loading i.e. is the key press condition correct and working?

I'll take a look at dop2000's example next.