Index: hector_pose_estimation_core/include/hector_pose_estimation/input.h
===================================================================
--- hector_pose_estimation_core.orig/include/hector_pose_estimation/input.h
+++ hector_pose_estimation_core/include/hector_pose_estimation/input.h
@@ -79,7 +79,7 @@ public:
     return *variance_;
   }
 
-  virtual bool hasVariance() const { return variance_; }
+  virtual bool hasVariance() const { return variance_ != NULL; }
   virtual Variance const &getVariance() { if (!variance_) variance_.reset(new Variance); return *variance_; }
   virtual Variance const &getVariance() const { return *variance_; }
   virtual Variance& variance() { if (!variance_) variance_.reset(new Variance); return *variance_; }
Index: hector_pose_estimation_core/src/system/imu_model.cpp
===================================================================
--- hector_pose_estimation_core.orig/src/system/imu_model.cpp
+++ hector_pose_estimation_core/src/system/imu_model.cpp
@@ -51,7 +51,7 @@ GyroModel::~GyroModel()
 bool GyroModel::init(PoseEstimation& estimator, System &system, State& state)
 {
   bias_ = state.addSubState<3,3>(this, system.getName() + "_bias");
-  return bias_;
+  return bias_ != NULL;
 }
 
 void GyroModel::getPrior(State &state)
@@ -113,7 +113,7 @@ AccelerometerModel::~AccelerometerModel(
 bool AccelerometerModel::init(PoseEstimation& estimator, System &system, State& state)
 {
   bias_ = state.addSubState<3,3>(this, system.getName() + "_bias");
-  return bias_;
+  return bias_ != NULL;
 }
 
 void AccelerometerModel::getPrior(State &state)