Index: trunk/MagicSoft/Mars/Changelog
===================================================================
--- trunk/MagicSoft/Mars/Changelog	(revision 8029)
+++ trunk/MagicSoft/Mars/Changelog	(revision 8030)
@@ -32,4 +32,6 @@
      - fixed a bug which caused the spectra to be normalized at 1GeV
        by default instead of the integral
+     - allow the MC slope to be -1. With the current code this should
+       not be a problem anymore.
 
    * mbase/MMath.cc, mbase/MAGIC.cc:
Index: trunk/MagicSoft/Mars/NEWS
===================================================================
--- trunk/MagicSoft/Mars/NEWS	(revision 8029)
+++ trunk/MagicSoft/Mars/NEWS	(revision 8030)
@@ -162,4 +162,7 @@
      was not using the integral anymore but a normalization energy of
      1GeV. It is now the integral again.
+
+   - sponde: Fixed a problem in the weighting which did not allow
+     a MC slope of -1.
 
 
Index: trunk/MagicSoft/Mars/mhflux/MMcSpectrumWeight.cc
===================================================================
--- trunk/MagicSoft/Mars/mhflux/MMcSpectrumWeight.cc	(revision 8029)
+++ trunk/MagicSoft/Mars/mhflux/MMcSpectrumWeight.cc	(revision 8030)
@@ -107,6 +107,6 @@
     fNameMcEvt   = "MMcEvt";
 
-    fNewSlope    = -1;
-    fOldSlope    = -1;
+    fNewSlope    = -9;
+    fOldSlope    = -9;
 
     fEnergyMin   = -1;
@@ -379,25 +379,15 @@
     }
 
-    //
-    // Sanity checks to be sure that we won't divide by zero later on
-    //
-    if (rh.GetSlopeSpec()==-1)
-    {
-        *fLog << err << "The MC Slope of the power law must be different of -1... exit" << endl;
-        return kFALSE;
-    }
-
     fOldSlope  = rh.GetSlopeSpec();
     fEnergyMin = rh.GetELowLim();
     fEnergyMax = rh.GetEUppLim();
 
-    if (fNewSlope==-1)
-    {
-        *fLog << inf << "The new slope of the power law is -1... no weighting applied." << endl;
+    if (fNewSlope==-9)
+    {
+        *fLog << inf << "The new slope of the power law is undefined (-9)... no weighting applied." << endl;
         fNewSlope = fOldSlope;
     }
 
     TString form(GetFormulaWeightsX());
-
     if (fFunc)
         delete fFunc;