Getting segmentation faults when setting text

[cedwards rbdc com]

Greetings,
In my program, I have a button that the user clicks to reset the text in
a text-entry area. When the button
is clicked, the handler I've written is supposed to set the text to
"default", but it causes a seg fault when I
click the button.
Here's the code that's relevant:

void reset_text(GtkWidget *widget, gpointer text_entry_box) {
  gtk_entry_set_text(GTK_ENTRY((GtkWidget *)text_entry_box), "default");

}

gtk_signal_connect(GTK_OBJECT(reset_button), "clicked",
GTK_SIGNAL_FUNC(reset_text),
                            text_entry_box);

What exactly am I doing wrong, and what should I do to fix it?