For some reason the keyboard shortcut (Ctrl+`) does not toggle show/hide
functions.

Selecting ToolsFormula AuditingFormula Auditing mode works fine, so I
cannot figure out why the key combination doesn't work as well.

I have changed regional (keyboard) settings from UK English Extended to just
UK keyboard to see if it made any difference, it didn't.

I know the `(grave) key works and have tried it with both Ctrl keys with no
luck.

Help please.