Remove the empty file /WMRootmenu
Run as root gtkserviceseup and check cgonfig to hav eit started at boot.
Edit as root /etc/slapt-get/and replace this line:
SOURCE=http://slackware.uk/slint/x86_64/slint-14.2/:PREFERRED
by this one
SOURCE=http://slackware.uk/slint/x86_64/slint-testing/:PREFERRED
Run these commands as root:
  slapt-get --add-keys
  slapt-get -u
  slapt-get --upgrade

Known issues:
the numlock visual indicator don't work properly here: it stays on when
numlock is swithed off.
I have seen case wher the keyboard layout widget give a wrng indication. 

TIP: to move a widget on the panel: hold middle-clik on it and move it
with the mouse