Photoshop :: CC Not Saving On OSX 10.8.4

I had worked on an image, came back to it the day after and my worked hadn't been saved, but I didn't remember closing the image without saving.
 
This is now happened a number of times on 3 machines. Whilst working in fullscreen mode and coming to the end of my work I pressed command+S. Pressing F twice to exit fullscreen mode, the progress bar at the bottom of the window didn't show and the red close button at the top left of the window didn't have a black dot in it (to signify something has changed which hasn't been saved).
 
When I press command+w to close to file, there is no prompt to save. The file just closes. On inspection of the modified date of the file, it appears that no save was executed at all. The date was from the previous day.
 
I have lost large amounts of work through this floor in the software. I have used PS since v1 so I am no novice, but this problem is really dangerous and needs sorting out as a matter of priority.