--- a/src/blitter/32bpp_base.cpp	Fri Aug 10 08:57:04 2007 +0000
+++ b/src/blitter/32bpp_base.cpp	Fri Aug 10 13:11:53 2007 +0000
@@ -56,7 +56,7 @@
 		stepx = 1;
 	}
 
-	this->SetPixel(video, x, y, color);
+	if (x > 0 && y > 0 && x < screen_width && y < screen_height) this->SetPixel(video, x, y, color);
 	if (dx > dy) {
 		frac = dy - (dx / 2);
 		while (x != x2) {

--- a/src/blitter/8bpp_base.cpp	Fri Aug 10 08:57:04 2007 +0000
+++ b/src/blitter/8bpp_base.cpp	Fri Aug 10 13:11:53 2007 +0000
@@ -60,7 +60,7 @@
 		stepx = 1;
 	}
 
-	this->SetPixel(video, x, y, color);
+	if (x > 0 && y > 0 && x < screen_width && y < screen_height) this->SetPixel(video, x, y, color);
 	if (dx > dy) {
 		frac = dy - (dx / 2);
 		while (x != x2) {