Index: /trunk/Ohana/src/kapa2/src/Center.c
===================================================================
--- /trunk/Ohana/src/kapa2/src/Center.c	(revision 41674)
+++ /trunk/Ohana/src/kapa2/src/Center.c	(revision 41675)
@@ -17,6 +17,7 @@
 
   // enforce integer center here?
-  image[0].picture.Xc = X;
-  image[0].picture.Yc = Y;
+  // NAN value means retain existing center
+  if (isfinite(X)) image[0].picture.Xc = X;
+  if (isfinite(Y)) image[0].picture.Yc = Y;
   if ((zoom != 0) && (zoom != -1)) {
     image[0].picture.expand = zoom;