I've got exactly the same problem here - code folding shortcut - and googling shows that we're not the only ones having it.
To make it clear:
-folding-related preferences are enabled,
-collapse and expand done by mouse clicks works fine,
-default folding key shortcut doesn't seem to be working (neither Windows nor Mac OS),
-remapped toggle folding key doesn't seem to be working (neither Windows nor Mac OS),
It would be just great if we'd get some heads up on this feature revision.
-structural / block-level folding (notepad++, sublime text like)