Tenuto + (unwanted) staccato

[Ralph Palmer]

Greetings -

I'm running Lilypond 2.8.4.1 on WinXP Pro SP2.

In the following snippet, I'm getting a staccato mark that I don't want,
and that seems extraneous. Is this a bug?

snippet:
%%%%%%%%%%%%%%%%%%%%%

\version "2.8.4.1"
\include "english.ly"

Music = {
        \clef treble
        \key c \major
        \time 3/4

         gs''8\<[ d''-_(] d'')\![ a'-_(] a')[ fs'] |
}

\score {
       \Music
       }

%%%%%%%%%%%%%%%%%%%%%%%%

Thank you for your time and attention,

Ralph
+++++++++++++++++++++++++
Ralph Palmer
Energy/Administrative Coordinator
Keene State College
Keene, NH 03435-2502