diff --git a/gtsam/base/blockMatrices.h b/gtsam/base/blockMatrices.h
index c5e0de43f..8bf8876a2 100644
--- a/gtsam/base/blockMatrices.h
+++ b/gtsam/base/blockMatrices.h
@@ -227,7 +227,7 @@ public:
     assertInvariants();
     size_t actualBlock = block + blockStart_;
     checkBlock(actualBlock);
-    return variableColOffsets_[actualBlock] - variableColOffsets_[blockStart_];
+    return variableColOffsets_[actualBlock];
   }
 
   size_t& rowStart() { return rowStart_; }
@@ -484,7 +484,7 @@ public:
     assertInvariants();
     size_t actualBlock = block + blockStart_;
     checkBlock(actualBlock);
-    return variableColOffsets_[actualBlock] - variableColOffsets_[blockStart_];
+    return variableColOffsets_[actualBlock];
   }
 
   size_t& blockStart() { return blockStart_; }
diff --git a/gtsam/linear/HessianFactor.cpp b/gtsam/linear/HessianFactor.cpp
index 1bc021689..242b14a6a 100644
--- a/gtsam/linear/HessianFactor.cpp
+++ b/gtsam/linear/HessianFactor.cpp
@@ -41,6 +41,9 @@
 #include <boost/numeric/ublas/vector_proxy.hpp>
 #include <boost/numeric/ublas/blas.hpp>
 
+#include <gtsam/3rdparty/Eigen/Core>
+#include <gtsam/3rdparty/Eigen/Dense>
+
 #include <sstream>
 
 using namespace std;
@@ -236,6 +239,11 @@ void HessianFactor::updateATA(const HessianFactor& update, const Scatter& scatte
   }
   toc(1, "slots");
 
+  if(debug) {
+    this->print("Updating this: ");
+    update.print("with: ");
+  }
+
   // Apply updates to the upper triangle
   tic(2, "update");
   assert(this->info_.nBlocks() - 1 == scatter.size());
@@ -246,19 +254,33 @@ void HessianFactor::updateATA(const HessianFactor& update, const Scatter& scatte
       if(slot2 > slot1) {
         if(debug)
           cout << "Updating (" << slot1 << "," << slot2 << ") from (" << j1 << "," << j2 << ")" << endl;
-        ublas::noalias(this->info_(slot1, slot2)) += update.info_(j1,j2);
+//        ublas::noalias(this->info_(slot1, slot2)) += update.info_(j1,j2);
+        Eigen::Map<Eigen::MatrixXd>(&matrix_(0,0), matrix_.size1(), matrix_.size2()).block(
+            info_.offset(slot1), info_.offset(slot2), info_(slot1,slot2).size1(), info_(slot1,slot2).size2()) +=
+                Eigen::Map<Eigen::MatrixXd>(&update.matrix_(0,0), update.matrix_.size1(), update.matrix_.size2()).block(
+                    update.info_.offset(j1), update.info_.offset(j2), update.info_(j1,j2).size1(), update.info_(j1,j2).size2());
       } else if(slot1 > slot2) {
         if(debug)
           cout << "Updating (" << slot2 << "," << slot1 << ") from (" << j1 << "," << j2 << ")" << endl;
-        ublas::noalias(this->info_(slot2, slot1)) += ublas::trans(update.info_(j1,j2));
+//        ublas::noalias(this->info_(slot2, slot1)) += ublas::trans(update.info_(j1,j2));
+        Eigen::Map<Eigen::MatrixXd>(&matrix_(0,0), matrix_.size1(), matrix_.size2()).block(
+            info_.offset(slot2), info_.offset(slot1), info_(slot2,slot1).size1(), info_(slot2,slot1).size2()) +=
+                Eigen::Map<Eigen::MatrixXd>(&update.matrix_(0,0), update.matrix_.size1(), update.matrix_.size2()).block(
+                    update.info_.offset(j1), update.info_.offset(j2), update.info_(j1,j2).size1(), update.info_(j1,j2).size2()).transpose();
       } else {
         if(debug)
           cout << "Updating (" << slot1 << "," << slot2 << ") from (" << j1 << "," << j2 << ")" << endl;
-        Block thisBlock(this->info_(slot1, slot2));
-        constBlock updateBlock(update.info_(j1,j2));
-        ublas::noalias(ublas::symmetric_adaptor<Block,ublas::upper>(thisBlock)) +=
-            ublas::symmetric_adaptor<constBlock,ublas::upper>(updateBlock);
+//        Block thisBlock(this->info_(slot1, slot2));
+//        constBlock updateBlock(update.info_(j1,j2));
+//        ublas::noalias(ublas::symmetric_adaptor<Block,ublas::upper>(thisBlock)) +=
+//            ublas::symmetric_adaptor<constBlock,ublas::upper>(updateBlock);
+        Eigen::Map<Eigen::MatrixXd>(&matrix_(0,0), matrix_.size1(), matrix_.size2()).block(
+            info_.offset(slot1), info_.offset(slot2), info_(slot1,slot2).size1(), info_(slot1,slot2).size2()).triangularView<Eigen::Upper>() +=
+                Eigen::Map<Eigen::MatrixXd>(&update.matrix_(0,0), update.matrix_.size1(), update.matrix_.size2()).block(
+                    update.info_.offset(j1), update.info_.offset(j2), update.info_(j1,j2).size1(), update.info_(j1,j2).size2());
       }
+      if(debug) cout << "Updating block " << slot1 << "," << slot2 << " from block " << j1 << "," << j2 << "\n";
+      if(debug) this->print();
     }
   }
   toc(2, "update");
diff --git a/gtsam/linear/JacobianFactor.cpp b/gtsam/linear/JacobianFactor.cpp
index bf3f193cd..2bce79f2c 100644
--- a/gtsam/linear/JacobianFactor.cpp
+++ b/gtsam/linear/JacobianFactor.cpp
@@ -478,7 +478,7 @@ namespace gtsam {
     firstNonzeroBlocks_.resize(this->size1());
     for(size_t row=0; row<size1(); ++row) {
       if(debug) cout << "row " << row << " varpos " << varpos << " Ab_.offset(varpos)=" << Ab_.offset(varpos) << " Ab_.offset(varpos+1)=" << Ab_.offset(varpos+1) << endl;
-      while(varpos < this->keys_.size() && Ab_.offset(varpos+1) <= row)
+      while(varpos < this->keys_.size() && Ab_.offset(varpos+1)-Ab_.offset(0) <= row)
         ++ varpos;
       firstNonzeroBlocks_[row] = varpos;
       if(debug) cout << "firstNonzeroVars_[" << row << "] = " << firstNonzeroBlocks_[row] << endl;
diff --git a/gtsam/linear/tests/testGaussianJunctionTree.cpp b/gtsam/linear/tests/testGaussianJunctionTree.cpp
index 4e75537eb..7d68a3682 100644
--- a/gtsam/linear/tests/testGaussianJunctionTree.cpp
+++ b/gtsam/linear/tests/testGaussianJunctionTree.cpp
@@ -24,6 +24,7 @@
 #include <boost/assign/std/set.hpp> // for operator +=
 using namespace boost::assign;
 
+#include <gtsam/base/debug.h>
 #include <gtsam/linear/GaussianJunctionTree.h>
 #include <gtsam/inference/BayesTree-inl.h>
 
@@ -66,6 +67,9 @@ GaussianFactorGraph createChain() {
  */
 TEST( GaussianJunctionTree, eliminate )
 {
+
+  SETDEBUG("updateATA",true);
+
 	GaussianFactorGraph fg = createChain();
 	GaussianJunctionTree junctionTree(fg);
 	BayesTree<GaussianConditional>::sharedClique rootClique = junctionTree.eliminate();
diff --git a/gtsam/linear/tests/testHessianFactor.cpp b/gtsam/linear/tests/testHessianFactor.cpp
index 69ca0f92b..9206d300a 100644
--- a/gtsam/linear/tests/testHessianFactor.cpp
+++ b/gtsam/linear/tests/testHessianFactor.cpp
@@ -16,6 +16,7 @@
  * @created Dec 15, 2010
  */
 
+#include <gtsam/base/debug.h>
 #include <gtsam/linear/HessianFactor.h>
 #include <gtsam/linear/JacobianFactor.h>
 #include <gtsam/linear/GaussianFactorGraph.h>
@@ -207,6 +208,7 @@ TEST(GaussianFactor, eliminate2 )
 
 /* ************************************************************************* */
 TEST_UNSAFE(GaussianFactor, eliminateUnsorted) {
+
   JacobianFactor::shared_ptr factor1(
       new JacobianFactor(0,
                          Matrix_(3,3,