I've got a vanilla install of WebStorm (I'm a new convert and still learning my way around it) but I'm finding some shortcuts are being ignored or processed in an unusual way.
For example I've just discovered Emmet. Tab expansion works fine but the Shift-Alt-Open Bracket shortcut opens the version control tab (shortcut Alt-9) rather than goes to the previous Emmet edit point as it should. The Shift-Alt-Close Bracket shortcut is completely ignored. Both actions work if selected through the navigate menu though so Emmet seems to be working fine.