gEDA: scroll wheel causes segmentation fault

[Antonio <antonio-at-NOSPAMprojetos_dot_etc_dot_br>]

With the mouse pointer over gschem, and rolling the mouse wheel causes a
seg fault:


(gschem:6237): Gtk-CRITICAL **: gtk_range_get_adjustment: assertion
`GTK_IS_RANGE (range)' failed
Falha de segmentação


This is commom when you use strokes, pressing middle-button and
performing a stroke you may roll-up or roll-down the wheel.

Antonio
antonio@projetos.etc.br