Index: trunk/psModules/src/astrom/pmAstrometryDistortion.c
===================================================================
--- trunk/psModules/src/astrom/pmAstrometryDistortion.c	(revision 23989)
+++ trunk/psModules/src/astrom/pmAstrometryDistortion.c	(revision 39926)
@@ -335,5 +335,7 @@
 
     psFree (fpa->fromTPA);
-    fpa->fromTPA = psPlaneTransformInvert(NULL, fpa->toTPA, *region, 50);
+    psPlaneTransform *myPT = psPlaneTransformAlloc(fpa->toTPA->x->nX+4, fpa->toTPA->x->nY+4);
+    fpa->fromTPA = psPlaneTransformInvert(myPT, fpa->toTPA, *region, 50);
+    psFree (myPT);
     psFree (region);