--- draw.c.orig	Mon May 15 09:07:15 2000
+++ draw.c	Wed May 17 08:20:39 2000
@@ -571,20 +571,21 @@
 	Value *v;
 
 	if (stackMode) {
 		bzero(stackBuffer,samplesOnScreen*sizeof(double));
 	}
 	else {
 		// Free
 		if (stackBuffer) {
 			free(stackBuffer);
 			stackBuffer = NULL;
+			stackBufferSize = -1;
 		}
 	}
 
 	v = values;
 	while(v) {
 		gdk_gc_set_foreground(gc,&colors[v->color + MINGRAPHCOLOR]);
 
 		drawValue(v);
 
 		v = v->next;