Index: /trunk/psModules/src/objects/models/pmModel_PGAUSS.c
===================================================================
--- /trunk/psModules/src/objects/models/pmModel_PGAUSS.c	(revision 10194)
+++ /trunk/psModules/src/objects/models/pmModel_PGAUSS.c	(revision 10195)
@@ -51,6 +51,6 @@
         dPAR[PM_PAR_YPOS] = q*(2.0*py/PAR[PM_PAR_SYY] + X*PAR[PM_PAR_SXY]);
         // the extra factor of 2 below is needed to avoid excessive swings
-        dPAR[PM_PAR_SXX] =  +2.0*q*px*px/PAR[PM_PAR_SXX];
-        dPAR[PM_PAR_SYY] =  +2.0*q*py*py/PAR[PM_PAR_SYY];
+        dPAR[PM_PAR_SXX] =  +4.0*q*px*px/PAR[PM_PAR_SXX];
+        dPAR[PM_PAR_SYY] =  +4.0*q*py*py/PAR[PM_PAR_SYY];
         dPAR[PM_PAR_SXY] = -q*X*Y;
     }