diff --git a/src/camel/Class/ClassEngine.cc b/src/camel/Class/ClassEngine.cc
index ec03e4edcaf118a82166651bcbf1f413f536eb6c..9abb92f6e980b6716c5cd2bc0dbd9acbcf2d4c25 100644
--- a/src/camel/Class/ClassEngine.cc
+++ b/src/camel/Class/ClassEngine.cc
@@ -654,7 +654,6 @@ double ClassEngine::get_Dv(double z)
   //call to fill pvecback
   background_at_tau(&ba,tau,ba.long_info,ba.inter_normal, &index, pvecback);
 
-
   double H_z=pvecback[ba.index_bg_H];
   double D_ang=pvecback[ba.index_bg_ang_distance];
 #ifdef DBUG
@@ -663,8 +662,7 @@ double ClassEngine::get_Dv(double z)
 #endif
   double D_v;
 
-  D_v=pow(D_ang*(1+z),2)*z/H_z;
-  D_v=pow(D_v,1./3.);
+  D_v=std::pow(D_ang*(1+z)*D_ang*(1+z)*z/H_z,1./3.);
 #ifdef DBUG
   cout << D_v << endl;
 #endif
diff --git a/src/camel/Class/MnClassEngine.hh b/src/camel/Class/MnClassEngine.hh
index 516875c76199f57123a7989c0aa169dab5cdbdc7..e7c3f606221848d12d15a17b7960cf244744331c 100644
--- a/src/camel/Class/MnClassEngine.hh
+++ b/src/camel/Class/MnClassEngine.hh
@@ -38,7 +38,7 @@ public:
 		const std::string& prefile);
 
   // destructor
-  ~MnClassEngine();
+  virtual ~MnClassEngine();
 
   //this will update the CLASS computations for a realization of par 
   //conistent with the MnUserVariables
diff --git a/src/camel/Lensing/Chi2Lensing.hh b/src/camel/Lensing/Chi2Lensing.hh
index d2f5a15d140b764cb3196c65c768feac0da32784..0c499fa039fd52016c6014526f03b19bc7873cec 100644
--- a/src/camel/Lensing/Chi2Lensing.hh
+++ b/src/camel/Lensing/Chi2Lensing.hh
@@ -35,7 +35,7 @@ public:
   Chi2Lensing(LensingLikelihood* ll, const Variables& pars,Engine* _klass);
 
   // destructor
-  ~Chi2Lensing();
+  virtual ~Chi2Lensing();
 
   //operator to override: must return something comptible with -2log(L)
   double chi2_eff(const std::vector<double>& par) const;
diff --git a/src/camel/MCMC/MCMC_adaptive.cc b/src/camel/MCMC/MCMC_adaptive.cc
index 07ab8570f0876bd49dd9451c129b965bb6b9fb89..20c70cd91b2ffa8d2a60ba31cce6655b70a6c412 100644
--- a/src/camel/MCMC/MCMC_adaptive.cc
+++ b/src/camel/MCMC/MCMC_adaptive.cc
@@ -323,7 +323,8 @@ void MCMC_adaptive::fill_chain(pdf* target_func, pdf* proposal,int init_step, co
 	    int gate=_bunchSize;
 	    if(i%gate==0)
 	      {
-		if (_verbose) cout << "dump at index " << i << " from " << i-gate << " to " << i-1 << endl;
+              //if (_verbose) cout << "dump at index " << i << " from " << i-gate << " to " << i-1 << endl;
+              cout << i << " written" <<endl;
 		chain_running.open (chain_run_name, fstream::app);
 		
 		for(int k=i-gate; k<i; k++)
diff --git a/src/camel/MCMC/MCMC_sampler.cc b/src/camel/MCMC/MCMC_sampler.cc
index c093722a6e202f9ce893e7afff2d7cc90762efc1..b7717fed4a0a68c92751b9305e73bcd41b4f41ba 100644
--- a/src/camel/MCMC/MCMC_sampler.cc
+++ b/src/camel/MCMC/MCMC_sampler.cc
@@ -136,7 +136,7 @@ void MCMC_sampler::write_chain(char* str)
 
 }
 
-void MCMC_sampler::write_if_useful(vector<double>& vec,char* str)
+void MCMC_sampler::write_if_useful(vector<double>& vec,const char* str)
 {
 
   cout << "output written in:"<< str << endl;
@@ -149,7 +149,7 @@ void MCMC_sampler::write_if_useful(vector<double>& vec,char* str)
 
 } 
 
-void MCMC_sampler::write_vecHep(vector<HepVector >& vec,char* str)
+void MCMC_sampler::write_vecHep(vector<HepVector >& vec,const char* str)
 {
 
   cout << "output written in:"<< str << endl;
diff --git a/src/camel/MCMC/MCMC_sampler.hh b/src/camel/MCMC/MCMC_sampler.hh
index 8308828b68d1300f5f6e566fdaea63503a23f6ad..5b061a0d5a957bbffd3202801a60b47fa0002224 100644
--- a/src/camel/MCMC/MCMC_sampler.hh
+++ b/src/camel/MCMC/MCMC_sampler.hh
@@ -67,8 +67,8 @@ public:
   void compute_mean(int stop,HepVector mean);
   void write_rearranged_chain(char* str); //rec, value, lkh
   void set_par(Parser parser); // set parameters value using Parser
-  void write_if_useful(std::vector<double>& vec,char* str);
-  void write_vecHep(std::vector<HepVector >& vec,char* str);
+  void write_if_useful(std::vector<double>& vec,const char* str);
+  void write_vecHep(std::vector<HepVector >& vec,const char* str);
 
   
   //accessors
diff --git a/src/camel/MCMC/exec/mainMCMC.cc b/src/camel/MCMC/exec/mainMCMC.cc
index d3b85d2b223681c88b8c44f570f27cb0b0bad21b..3c0e1480db0c3d9dcaefa90148e3ac43974dde30 100644
--- a/src/camel/MCMC/exec/mainMCMC.cc
+++ b/src/camel/MCMC/exec/mainMCMC.cc
@@ -48,7 +48,12 @@ int main(int argc, char *argv[])
     std::cout << "output file " + fileName + " already exists: removing it"<<endl;
     remove_file(fileName);
   }
+  string ar_file=string("ar_vs_length_")+fileName;
+  string scale_file=string("scale_")+fileName;
+  string cor_file=string("prop_cov_")+fileName;
 
+  cout << "output files:" <<endl;
+  cout << ar_file << " " << scale_file << " " << cor_file << " " << endl;
 
   //MCMC specific parameters
   const string algo=parser.params.find<string>("algo","ada");
@@ -151,8 +156,7 @@ int main(int argc, char *argv[])
 
   if(use_ext_cov)
   {
-    cout << "Read proposal cov matrix.." << endl;
-    cout << proposal_cov.c_str() << endl;
+    cout << "Read proposal cov matrix=" << proposal_cov.c_str() << endl;
     proposal->set_cov(proposal_cov.c_str());
   }
   else {
@@ -245,21 +249,21 @@ int main(int argc, char *argv[])
          {ar_vs_length.push_back(chain->acc_rate(0,step));}
      }
 
-   chain->write_if_useful(ar_vs_length,"ar_vs_length.txt");
+   chain->write_if_useful(ar_vs_length,ar_file.c_str());
 
    if(algo=="ada")
    {
      MCMC_adaptive* ada=dynamic_cast<MCMC_adaptive*>(chain);
-     chain->write_if_useful(proposal->_scale_vs_length,"scale_vs_length.txt");
+     chain->write_if_useful(proposal->_scale_vs_length,scale_file.c_str());
 
-     ofstream f("corr.txt");
+     ofstream f(cor_file.c_str());
      if(!f) {
        cout << "Error in file creation!";
      }
      f << ada->mean() << endl //mean
        << proposal->Get_cov_matrix() << endl; //cov matrix
      f.close();
-     cout<<"output written in:corr.txt"<<endl;;
+     cout<<"proposal cov written in " << cor_file <<endl;;
    }
 
    delete chi2;