I can't reproduce this with Scite 330, but it happens sometimes in Komodo (8.0.1),
and Komodo passes the Home() command directly to Scintilla.
This is our horizontal slop policy for all buffers (not exposed via a pref):
The problem happens with documents that contain lines that extend to the right
of the view. Position the caret at the end of one of those lines which has
a non-zero left-side run of whitespace. Press Home.
The caret always moves to the first non-blank character of the line, which is correct.
However, sometimes, but not always, the caret is at offset 0, while we would expect
the slop to cause scintilla to show all the leading whitespace.