diff --git a/source/src/XMLParser.cc b/source/src/XMLParser.cc
index 452a0e75..84afa29b 100644
--- a/source/src/XMLParser.cc
+++ b/source/src/XMLParser.cc
@@ -157,7 +157,11 @@ namespace marlin{
         // preprocess groups: ---------------------------------------------------------------------------------
         // simply copy all group parameters to the processors
         // and then copy the processors to the root node <Marlin>
-        while( (section = root->IterateChildren( "group", section ) )  != 0  ){
+        // 'section' comes from above as first execute child, get the next section so we
+        // do not cleanup the execute section in loop body below, only the groups
+        TiXmlNode* nextSection = root->IterateChildren("group", section);
+        while((section = nextSection) != 0){
+            nextSection = root->IterateChildren("group", section);
 
             std::vector<TiXmlNode*> groupParams ;
 
@@ -527,9 +531,10 @@ namespace marlin{
             condition = aCondition ;
 
         TiXmlNode* child = 0 ;
-        while( ( child = current->IterateChildren( "if" , child )  )  != 0  ){
-
-            processconditions( child , getAttribute( child, "condition") ) ;  
+        TiXmlNode* nextChild = current->IterateChildren("if" , child);
+        while((child = nextChild) != 0){
+            nextChild = current->IterateChildren("if" , child);
+            processconditions( child , getAttribute( child, "condition") ) ; // might clean child
         }
 
         while( ( child = current->IterateChildren( "processor" , child )  )  != 0  ) {
@@ -900,8 +905,9 @@ namespace marlin{
         }
 
         TiXmlNode* child = 0 ;
-        while( ( child = section->IterateChildren( child ) )  != 0  ){
-
+        TiXmlNode* nextChild = section->IterateChildren( child );
+        while((child = nextChild) != 0){
+            nextChild = section->IterateChildren(child);
             if( std::string( child->Value() )  == "group" ) {
 
                 // find group definition in root node