You should check some preferences.
First of all, check your system preferences to make sure, ctrl+1 is not caught by some system event - that was the case for me when I checked it.
- Open System Preferences
- Choose Keyboard
- Choose Shortcuts (the second tab)
- On the left select box choose Mission Control
- Check in the right box, if it is selected as keyboard shortcut for desktop 1 fir instance.
- If yes, uncheck this and try again
- If not, you may search through the other shortcuts in application shortcuts, too
I guess you have only one desktop / space and I also guess that you have as many shortcuts listed as you have desktops - 3 in my case. That's probably why ctrl+2 works.
If you still have trouble, check the Sublime Preferences and especially your user preferences. Easiest way to do this is open a terminal and type
cd ~/Library/Application\ Support/Sublime\ Text\ 2/Packages/
grep -ri 'ctrl+1' .
If you find something more than those 3 lines in Default (one for each os) containing
{ "keys": ["ctrl+1"], "command": "focus_group", "args": { "group": 0 } }
You have probably overridden this shortcut with something else. You may think of changing this in the corresponding file, or resetting it to the above mentioned command in your
User/Default (OSX).sublime-keymap
by adding the line above to it (be careful with the commas - the file must be valid json).