diff --git a/src/classes/PFunction.cpp b/src/classes/PFunction.cpp
index 51de6fbb..43b9b6c5 100644
--- a/src/classes/PFunction.cpp
+++ b/src/classes/PFunction.cpp
@@ -492,6 +492,7 @@ Double_t PFunction::EvalNode(PFuncTreeNode &node)
       if (denominator == 0.0) {
         cerr << endl << "**PANIC ERROR**: PFunction::EvalNode: division by 0.0";
         cerr << endl << "**PANIC ERROR**: PFunction::EvalNode: requested operation: " << EvalNode(node.children[0]) << "/" << EvalNode(node.children[1]);
+        cerr << endl << ">> " << fFuncString.Data() << endl;
         cerr << endl;
         assert(0);
       }
diff --git a/src/classes/PMusrCanvas.cpp b/src/classes/PMusrCanvas.cpp
index ac5e5ab5..35c4e4ad 100644
--- a/src/classes/PMusrCanvas.cpp
+++ b/src/classes/PMusrCanvas.cpp
@@ -5328,9 +5328,9 @@ void PMusrCanvas::SaveDataAscii()
             fout << dumpVector[j].dataErr[i] << ", ";
         } else {
           if (dumpVector[j].dataErr.size() > 0)
-            fout << ", , , ";
+            fout << " , , , ";
           else
-            fout << ", , ";
+            fout << " , , ";
         }
       }
       // write theory
@@ -5339,7 +5339,7 @@ void PMusrCanvas::SaveDataAscii()
           fout << dumpVector[j].theoryX[i] << ", ";
           fout << dumpVector[j].theory[i] << ", ";
         } else {
-          fout << ", , ";
+          fout << " , , ";
         }
       }
       // write last theory entry
@@ -5347,7 +5347,7 @@ void PMusrCanvas::SaveDataAscii()
         fout << dumpVector[dumpVector.size()-1].theoryX[i] << ", ";
         fout << dumpVector[dumpVector.size()-1].theory[i];
       } else {
-        fout << ", ";
+        fout << " , ";
       }
       fout << endl;
     }
diff --git a/src/classes/PRunMuMinus.cpp b/src/classes/PRunMuMinus.cpp
index 0523bf67..4e4f95fa 100644
--- a/src/classes/PRunMuMinus.cpp
+++ b/src/classes/PRunMuMinus.cpp
@@ -211,7 +211,7 @@ Double_t PRunMuMinus::CalcChiSquareExpected(const std::vector<Double_t>& par)
 // CalcMaxLikelihood
 //--------------------------------------------------------------------------
 /**
- * <p>Calculate log max-likelihood.
+ * <p>Calculate log max-likelihood. See http://pdg.lbl.gov/index.html
  *
  * <b>return:</b>
  * - log max-likelihood value
@@ -258,13 +258,14 @@ Double_t PRunMuMinus::CalcMaxLikelihood(const std::vector<Double_t>& par)
     time = fData.GetDataTimeStart() + (Double_t)i*fData.GetDataTimeStep();
     // calculate theory for the given parameter set
     theo = fTheory->Func(time, par, fFuncValues);
-    // check if data value is not too small
-    if (fData.GetValue()->at(i) > 1.0e-9)
-      data = fData.GetValue()->at(i);
-    else
-      data = 1.0e-9;
-    // add maximum log likelihood contribution of bin i
-    mllh -= data*TMath::Log(theo) - theo - TMath::LnGamma(data+1);
+
+    data = fData.GetValue()->at(i);
+
+    if (data > 1.0e-9) {
+      mllh += (theo-data) + data*log(data/theo);
+    } else {
+      mllh += (theo-data);
+    }
   }
 
   return mllh;
diff --git a/src/classes/PRunNonMusr.cpp b/src/classes/PRunNonMusr.cpp
index 18ca884c..2814ec11 100644
--- a/src/classes/PRunNonMusr.cpp
+++ b/src/classes/PRunNonMusr.cpp
@@ -144,7 +144,7 @@ Double_t PRunNonMusr::CalcChiSquareExpected(const std::vector<Double_t>& par)
  */
 Double_t PRunNonMusr::CalcMaxLikelihood(const std::vector<Double_t>& par)
 {
-  cout << endl << "PRunSingleHisto::CalcMaxLikelihood(): not implemented yet ..." << endl;
+  cout << endl << "PRunNonMusr::CalcMaxLikelihood(): not implemented yet ..." << endl;
 
   return 1.0;
 }
diff --git a/src/classes/PRunSingleHisto.cpp b/src/classes/PRunSingleHisto.cpp
index 3a6f11c4..7dc81d05 100644
--- a/src/classes/PRunSingleHisto.cpp
+++ b/src/classes/PRunSingleHisto.cpp
@@ -296,7 +296,7 @@ Double_t PRunSingleHisto::CalcChiSquareExpected(const std::vector<Double_t>& par
 // CalcMaxLikelihood (public)
 //--------------------------------------------------------------------------
 /**
- * <p>Calculate log maximum-likelihood.
+ * <p>Calculate log maximum-likelihood. See http://pdg.lbl.gov/index.html
  *
  * <b>return:</b>
  * - log maximum-likelihood value
@@ -381,13 +381,14 @@ Double_t PRunSingleHisto::CalcMaxLikelihood(const std::vector<Double_t>& par)
     // calculate theory for the given parameter set
     theo = N0*TMath::Exp(-time/tau)*(1+fTheory->Func(time, par, fFuncValues))+bkg;
     theo *= normalizer;
-    // check if data value is not too small
-    if (fData.GetValue()->at(i) > 1.0e-9)
-      data = normalizer*fData.GetValue()->at(i);
-    else
-      data = 1.0e-9;
-    // add maximum log likelihood contribution of bin i
-    mllh -= data*TMath::Log(theo) - theo - TMath::LnGamma(data+1);
+
+    data = normalizer*fData.GetValue()->at(i);
+
+    if (data > 1.0e-9) {
+      mllh += (theo-data) + data*log(data/theo);
+    } else {
+      mllh += (theo-data);
+    }
   }
 
   return mllh;