This hurts to have to ask, but here it is:
I have been using a script file to load optimal linewidth, grid, pad
diameter (etc.) menu choices for the different editors whenever I open a new
file. (This is another method of loading parameters into the "Options
Assign" menu, of course.)
This would overwrite any default Eagle commands if they used the same key
combinations. I believe I overwrote the default +S into the "Options Assign" menu?