I'm finding that the set-mark-command command in emacs doesn't always work when I'm logged in with VNC.
When everything is working, I issue the set-mark command and move the point up or down a few lines, the region gets highlighted. Then if I issue the C-w (kill-region) command, the region is deleted. When it doesn't work, I issue the set-mark command and move the point up or down a few lines it does not highlight anything. Then typing C-w (kill-region) results in "The mark is not active now". I'm going to list the cases where it does and does not work and hopefully someone will have suggestions as to what's wrong.
When ssh'ing to my account, using emacs -nw, it always works.
When vnc'd to my account using twm window manager, it always works.
When vnc'd, using gnome and issuing C-@ (bound to set-mark-command), it works.
When vnc'd, using gnome and issuing M-x set-mark-command, it works.
When vnc'd, using gnome and issuing M-x set-mark, it DOES NOT work. In this case, it says "Mark set", but after moving the point, it gets deactivated.
When vnc'd, using gnome and issuing C-spc (bound to set-mark-command) it DOES NOT work. In this case I believe C-spc becomes unbound. When I type C-h k C-spc it displays nothing. However, M-x describe-bindings shows that C-spc is bound to set-mark-command.