cygwin x上で以下のようなエラーが出てgnuplotを使うことができません．どなたか解決策が分かる方いましたら教えて下さい．

octave:1> x = [0.0, 0.2, 0.4]
x =

0.00000 0.20000 0.40000

octave:2> plot(x, sin(x))
error: Invalid call to strcat. Correct usage is:

-- Function File: strcat (S1, S2, ...)

error: called from:
error: /usr/share/octave/3.4.0/m/help/print_usage.m at line 87, column 5
error: /usr/share/octave/3.4.0/m/strings/strcat.m at line 92, column 5
error: /usr/share/octave/3.4.0/m/plot/__gnuplot_get_var__.m at line 113, column 11
error: /usr/share/octave/3.4.0/m/plot/__go_draw_axes__.m at line 40, column 18
error: /usr/share/octave/3.4.0/m/plot/__go_draw_figure__.m at line 167, column 19
error: /usr/share/octave/3.4.0/m/plot/__gnuplot_drawnow__.m at line 86, column 5