--- PGraphics3D.java	2008-12-13 02:59:16.000000000 -0800
+++ PGraphics3Dfixed.java	2008-12-13 02:54:59.000000000 -0800
@@ -2657,6 +2657,23 @@
     float centerX = x + hr;
     float centerY = y + vr;
 
+    if (stop - start >= TWO_PI) {
+      start = 0;
+      stop = TWO_PI;
+
+    } else {
+      while (start < 0) {
+        start += TWO_PI;
+        stop += TWO_PI;
+      }
+      if (start > stop) {
+        float temp = start;
+        start = stop;
+        stop = temp;
+      }
+    }
+
+
     if (fill) {
       // shut off stroke for a minute
       boolean savedStroke = stroke;