delete not working

[Ofnuts]

Open Windows>Dockable dialogs>Device status. This will opend a window showing your which tools is associated with which pointer. You will normally see the "core pointer" (that lumps together the non-pressure devices: mouse, trackpad, trackpoint...) and the two stylus ends (since you have a Wacom, I assume it is double-ended so you distinct device for each end of the stylus).

Now, if you hit the Shift-E (which is what you mean by "Erase key"?) does the tool of any device changes?