Comment 4 for bug 699493

This is a bug, and is succinctlydescribed. "+" and "-" don't work in keyboard shortcuts.

The other suggesion, LP:700742 does not explicity duplicate this report, and whilst application of that patch would cause this bug to be fixed / invalid, until that patch is applied, this bug remains valid.

Please see my comments on the other bug, as to why I think it is not necessarily a good approach.