Index: branches/ProblemInstancesRegressionAndClassification/HeuristicLab.Problems.DataAnalysis.Symbolic.Regression/3.4/MultiObjective/SymbolicRegressionMultiObjectiveProblem.cs
===================================================================
--- branches/ProblemInstancesRegressionAndClassification/HeuristicLab.Problems.DataAnalysis.Symbolic.Regression/3.4/MultiObjective/SymbolicRegressionMultiObjectiveProblem.cs	(revision 7771)
+++ branches/ProblemInstancesRegressionAndClassification/HeuristicLab.Problems.DataAnalysis.Symbolic.Regression/3.4/MultiObjective/SymbolicRegressionMultiObjectiveProblem.cs	(revision 7805)
@@ -26,4 +26,5 @@
 using HeuristicLab.Parameters;
 using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
+using HeuristicLab.Problems.Instances;
 
 namespace HeuristicLab.Problems.DataAnalysis.Symbolic.Regression {
@@ -31,5 +32,6 @@
   [StorableClass]
   [Creatable("Problems")]
-  public class SymbolicRegressionMultiObjectiveProblem : SymbolicDataAnalysisMultiObjectiveProblem<IRegressionProblemData, ISymbolicRegressionMultiObjectiveEvaluator, ISymbolicDataAnalysisSolutionCreator>, IRegressionProblem {
+  public class SymbolicRegressionMultiObjectiveProblem : SymbolicDataAnalysisMultiObjectiveProblem<IRegressionProblemData, ISymbolicRegressionMultiObjectiveEvaluator, ISymbolicDataAnalysisSolutionCreator>, IRegressionProblem,
+    IProblemInstanceConsumer<IRegressionProblemData>, IProblemInstanceExporter<IRegressionProblemData> {
     private const double PunishmentFactor = 10;
     private const int InitialMaximumTreeDepth = 8;
@@ -111,4 +113,19 @@
       }
     }
+
+    #region Import & Export
+    public new void Load(IRegressionProblemData data) {
+      base.Load(data);
+    }
+
+    public IRegressionProblemData Export() {
+      if (ProblemData is IRegressionProblemData)
+        return ProblemData;
+      else {
+        IRegressionProblemData regData = new RegressionProblemData(ProblemData.Dataset, ProblemData.AllowedInputVariables, ProblemData.TargetVariable);
+        return base.Export(regData);
+      }
+    }
+    #endregion
   }
 }
Index: branches/ProblemInstancesRegressionAndClassification/HeuristicLab.Problems.DataAnalysis.Symbolic.Regression/3.4/SingleObjective/SymbolicRegressionSingleObjectiveProblem.cs
===================================================================
--- branches/ProblemInstancesRegressionAndClassification/HeuristicLab.Problems.DataAnalysis.Symbolic.Regression/3.4/SingleObjective/SymbolicRegressionSingleObjectiveProblem.cs	(revision 7771)
+++ branches/ProblemInstancesRegressionAndClassification/HeuristicLab.Problems.DataAnalysis.Symbolic.Regression/3.4/SingleObjective/SymbolicRegressionSingleObjectiveProblem.cs	(revision 7805)
@@ -32,5 +32,5 @@
   [Creatable("Problems")]
   public class SymbolicRegressionSingleObjectiveProblem : SymbolicDataAnalysisSingleObjectiveProblem<IRegressionProblemData, ISymbolicRegressionSingleObjectiveEvaluator, ISymbolicDataAnalysisSolutionCreator>, IRegressionProblem,
-    IProblemInstanceConsumer<RegressionProblemData>, IProblemInstanceExporter<RegressionProblemData> {
+    IProblemInstanceConsumer<IRegressionProblemData>, IProblemInstanceExporter<IRegressionProblemData> {
     private const double PunishmentFactor = 10;
     private const int InitialMaximumTreeDepth = 8;
@@ -115,14 +115,14 @@
 
     #region Import & Export
-    public void Load(RegressionProblemData data) {
+    public new void Load(IRegressionProblemData data) {
       base.Load(data);
     }
 
-    public RegressionProblemData Export() {
-      if (ProblemData is RegressionProblemData)
-        return (RegressionProblemData)ProblemData;
+    public IRegressionProblemData Export() {
+      if (ProblemData is IRegressionProblemData)
+        return ProblemData;
       else {
-        RegressionProblemData regData = new RegressionProblemData(ProblemData.Dataset, ProblemData.AllowedInputVariables, ProblemData.TargetVariable);
-        return (RegressionProblemData)base.Export(regData);
+        IRegressionProblemData regData = new RegressionProblemData(ProblemData.Dataset, ProblemData.AllowedInputVariables, ProblemData.TargetVariable);
+        return base.Export(regData);
       }
     }
