Index: trunk/psLib/src/math/psMinimizePolyFit.c
===================================================================
--- trunk/psLib/src/math/psMinimizePolyFit.c	(revision 37510)
+++ trunk/psLib/src/math/psMinimizePolyFit.c	(revision 37515)
@@ -702,4 +702,5 @@
     // these scaling values put the dynamic range of the data into some vaguely sensible location
     bool scale = false;
+    bool median_zero = false;
     double median = 0.0;
     double sigma = 1.0;
@@ -728,14 +729,11 @@
 	  sigma = 1.0;
 	}
-	if ((median == 0.0)&&(sigma == 1.0)) {
-	  scale = false;
-	}
-
-	if (median == 0.0) {
-	  if (sigma <= 0.0) {
-	    scale = false; // Try with what we started with.
-	  }
-	  else {
-	    median = 0.1 * sigma;
+	if (fabs(median) < 1e-10) {
+	  // CZW 2014-10-21: This median is small and close to zero.  This can cause issues with the
+	  // scaling,
+	  median_zero = true;
+	  if ((sigma == 1.0)||(sigma <= 0.0)) {
+	    // Don't bother scaling if sigma is unity (it's already scaled) or if the sigma calculation has gone wrong.
+	    scale = false;
 	  }
 	}
@@ -774,22 +772,28 @@
 #endif
 	}
+
 	for (psS32 i = 0; i <= poly->nX; i++) {
 	  poly->coeff[i] = 0.0;
 	  poly->coeffErr[i] = 0.0;
-	  
-	  for (psS32 j = 0; j <= poly->nX; j++) {
+	  if (median_zero) {  // If the median is zero, the obtained solution just needs to be scaled by the sigma values.
+	    poly->coeff[i]    = Zcoeff[i] * pow(1.0 / sigma,i);
+	    poly->coeffErr[i] = ZcoeffErr[i] * pow(1.0 / sigma,i);
+	  }
+	  else { // Otherwise, do the correct transformations by expanding the (x-m)/s terms.
+	    for (psS32 j = 0; j <= poly->nX; j++) {
 #if (CZW)
-	    printf("        %d %d %f %f %f %f => %f\n",
-		   i,j,Zcoeff[j],
-		   pow(1.0 / sigma,j) * pow(-1,j - i),
-		   pow(median,j - i),
-		   1.0 * psBinomialCoeff(j,i),
-		   Zcoeff[j] * pow(1.0 / sigma,j) * pow(-1,j  -i) * pow(median,j - i) * 1.0 * psBinomialCoeff(j,i)
-		   );
+	      printf("        %d %d %f %f %f %f => %f\n",
+		     i,j,Zcoeff[j],
+		     pow(1.0 / sigma,j) * pow(-1,j - i),
+		     pow(median,j - i),
+		     1.0 * psBinomialCoeff(j,i),
+		     Zcoeff[j] * pow(1.0 / sigma,j) * pow(-1,j  -i) * pow(median,j - i) * 1.0 * psBinomialCoeff(j,i)
+		     );
 #endif
-	    poly->coeff[i] += Zcoeff[j] * pow(1.0 / sigma,j) * pow(-1,j - i) * pow(median,j - i) * psBinomialCoeff(j,i);
-	    poly->coeffErr[i] += pow(ZcoeffErr[j] * pow(1.0 / sigma,j) * pow(-1,j - i) * pow(median,j - 1) * psBinomialCoeff(j,i),2);
+	      poly->coeff[i] += Zcoeff[j] * pow(1.0 / sigma,j) * pow(-1,j - i) * pow(median,j - i) * psBinomialCoeff(j,i);
+	      poly->coeffErr[i] += pow(ZcoeffErr[j] * pow(1.0 / sigma,j) * pow(-1,j - i) * pow(median,j - 1) * psBinomialCoeff(j,i),2);
+	    }
+	    poly->coeffErr[i] = sqrt(poly->coeffErr[i]);
 	  }
-	  poly->coeffErr[i] = sqrt(poly->coeffErr[i]);
 #if (CZW)
 	  printf("poly1d: unscaled parameters: %d %f %f\n",
@@ -800,5 +804,5 @@
 	psFree(ZcoeffErr);
 
-      }
+      } // End scaling block.
 	
         break;