Index: trunk/psphot/src/models/pmModel_STRAIL.c
===================================================================
--- trunk/psphot/src/models/pmModel_STRAIL.c	(revision 15843)
+++ trunk/psphot/src/models/pmModel_STRAIL.c	(revision 19881)
@@ -478,4 +478,5 @@
 {
     pmMoments *Smoments = source->moments;
+    pmPeak    *peak    = source->peak;
     psF32     *params  = model->params->data.F32;
 
@@ -484,7 +485,7 @@
     psEllipseMoments moments;
 
-    moments.x2 = PS_SQR(Smoments->Sx);
-    moments.y2 = PS_SQR(Smoments->Sy);
-    moments.xy = Smoments->Sxy;
+    moments.x2 = Smoments->Mxx;
+    moments.y2 = Smoments->Myy;
+    moments.xy = Smoments->Mxy;
     //sometimes these moment inputs are zero...why?
 
@@ -494,8 +495,9 @@
     shape = psEllipseAxesToShape(axes);
 
-    params[0] = Smoments->Sky;
-    params[1] = Smoments->Peak - Smoments->Sky;
-    params[2] = Smoments->x;
-    params[3] = Smoments->y;
+    params[PM_PAR_SKY]  = Smoments->Sky;
+    params[PM_PAR_I0]   = peak->flux;
+    params[PM_PAR_XPOS] = peak->xf;
+    params[PM_PAR_YPOS] = peak->yf;
+
     params[7] = 2 * axes.major;
     params[8] = axes.theta;