Keyboard shortcut changes in OS 10.8.5 & later

Total Spaces says that Command 1, Command 2, Command 3 shortcuts are already in use if the numbers are on the numeric keypad. If you assign them anyway, they don’t work. To what functions are these shortcuts already assigned? Is there a way to change them?

Oddly, on one of my backup drives in which OS 10.8.5 was installed on top of an existing installation of 10.7.5 these shortcuts using the numeric keypad still work. I would love to be able to use them again as they have been integrated into my work routine for years.

I’m sorry, I don’t immediately know what they could be assigned to. What version of OS X are you using?