diff --git a/pub/src/expr.cpp b/pub/src/expr.cpp
index 3845a53ca3a40f57f4320619e143df9c8526d126..1178c6410271b9881097cc949ba0f18e07ddf5a8 100644
--- a/pub/src/expr.cpp
+++ b/pub/src/expr.cpp
@@ -568,6 +568,7 @@ void CTree::tree_val( CTOut *ret, const CContext *ctx ) const
                 throw string( "2nd arg of conv must be scalar shift" );
             double shift = r.d;
             if ( kconv==-1 ) {
+                printf( "DEB no conv %i\n", n );
                 // Copy convolutand (= unconvoluted theory).
                 CTOut r;
                 // unconvoluted theory given by arg[0]:
@@ -575,6 +576,7 @@ void CTree::tree_val( CTOut *ret, const CContext *ctx ) const
                 for ( uint i=0; i<n; ++i )
                     ret->vd[i] = r.to_d(i) - shift;
             } else if ( NRead::iofmac("\\cv_mode")==-1 ) {
+                printf( "DEB conv %i %i step %f\n", n, nv, conv_step );
                 CTOut r;
                 CContext cvctx(*ctx);
                 vector<double> tt;
@@ -609,8 +611,8 @@ void CTree::tree_val( CTOut *ret, const CContext *ctx ) const
                             tt[i] = (*(ctx->fargs))[i] - sv->x[iv] - shift;
                         arg[0]->tree_val( &r, &cvctx );
                         for ( uint i=0; i<n; ++i )
-                            ret->vd[i] += r.to_d(i) * dx * sv->y[iv] /
-                                conv_norm;
+                            ret->vd[i] += r.to_d(i) * sv->y[iv] *
+                                dx / conv_norm;
                     }
                 }
             } else {
@@ -685,6 +687,7 @@ void CTree::tree_val( CTOut *ret, const CContext *ctx ) const
             vt = rarg.vd;
         }
         // evaluate function:
+        printf( "DEB set FRF context: %i -> %i,%i; x %f .. %f\n", ctx->k, frf.cr.k, frf.cr.j, vt[0], vt[vt.size()-1] );
         CContext cu_ctx( frf.cr.k, frf.cr.j );
         cu_ctx.set_fargs( &vt );
         frf.cr.fc->T->tree_val( ret, &cu_ctx );
@@ -801,7 +804,6 @@ uint CTree::setConvJ( uint k, uint j, uint kconv ) const
             throw "cannot convolute file " + strg(k) + " with resolution " +
                 strg(kconv) + ": number of scans does not match";
     }
-    
 }
 
 
diff --git a/pub/src/func.cpp b/pub/src/func.cpp
index 609207c116a50449ab7b5b813b20aa3d06b6c841..5d0e93f1e40c9affc62670cfba3bb27ca6841e07 100644
--- a/pub/src/func.cpp
+++ b/pub/src/func.cpp
@@ -117,7 +117,7 @@ double func_gauss (double x, double s) {
 double func_gaussnn (double x, double s) { // Gauss not normalized
     return s==0 ? 0 : exp(-x*x/(2*s*s)); }
 double func_cauchy (double x, double s) {
-    return s==0 ? 0 : 2*s/twopi/(x*x+s*s); }
+    return s==0 ? 0 : 2*fabs(s)/twopi/(x*x+s*s); }
 double func_kwwc( double v, double a){
     if( a<0.1 || a>2.0 ) return 0;
     return kwwcf( (float)v, (float)a ); }