Hi there
When I have both preferences set to true, Sublime is having issues:
"save_on_focus_lost": true,
"trim_trailing_white_space_on_save": true
For example I type var then hit the space bar and want to paste code with CTRL-v then it is losing focus, does a save and trims the white space. And my code is messed, the space after var is gone.
PS: I also posted this issue on GitHub at github.com/SublimeText/Issues/issues/170