On XCFE, some of the default (windowing system) bindings override those of SciTE (notably the Bookmarking commands).
Consult [http://scintilla.sourceforge.net/CommandValues.html] and add the following to .SciTEUser.properties :
# Remap some keys – # Ctrl-e = to end of line#NOT-YET Ctrl-a = to start of line
# Ctrl-2 = Next bookmark# Alt-2 = Toggle bookmark
user.shortcuts=\Ctrl+e|2314|\Ctrl+2|IDM_BOOKMARK_NEXT|\Alt+2|IDM_BOOKMARK_TOGGLE|
# Ctrl+a|2312|# Ctrl+a|Home|