Based on code + help from Alex Stapleton:
*Add Eigen/StdVector header.
Including it #includes<vector> and "Core" and generates a partial
specialization of std::vector<T> for T=Eigen::Matrix<...>
that will work even with vectorizable fixed-size Eigen types
(working around a design issue in the c++ STL)
*Add unit-test

CCMAIL: alex.stapleton@gmail.com
diff --git a/test/stdvector.cpp b/test/stdvector.cpp
new file mode 100644
index 0000000..4e6aa9e
--- /dev/null
+++ b/test/stdvector.cpp
@@ -0,0 +1,64 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra. Eigen itself is part of the KDE project.
+//
+// Copyright (C) 2008 Gael Guennebaud <g.gael@free.fr>
+//
+// Eigen is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 3 of the License, or (at your option) any later version.
+//
+// Alternatively, you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of
+// the License, or (at your option) any later version.
+//
+// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License and a copy of the GNU General Public License along with
+// Eigen. If not, see <http://www.gnu.org/licenses/>.
+
+#include "main.h"
+#include <Eigen/StdVector>
+
+template<typename MatrixType>
+void check_stdvector_fixedsize()
+{
+  MatrixType x = MatrixType::Random(), y = MatrixType::Random();
+  std::vector<MatrixType> v(10), w(20, y);
+  v[5] = x;
+  w[6] = v[5];
+  VERIFY_IS_APPROX(w[6], v[5]);
+  v = w;
+  for(int i = 0; i < 20; i++)
+  {
+    VERIFY_IS_APPROX(w[i], v[i]);
+  }
+  v.resize(21);
+  v[20] = x;
+  VERIFY_IS_APPROX(v[20], x);
+  v.resize(22,y);
+  VERIFY_IS_APPROX(v[21], y);
+  v.push_back(x);
+  VERIFY_IS_APPROX(v[22], x);
+}
+
+
+void test_stdvector()
+{
+  // some non vectorizable fixed sizes
+  CALL_SUBTEST(check_stdvector_fixedsize<Vector2f>());
+  CALL_SUBTEST(check_stdvector_fixedsize<Matrix3f>());
+  CALL_SUBTEST(check_stdvector_fixedsize<Matrix3d>());
+
+  // some vectorizable fixed sizes
+  CALL_SUBTEST(check_stdvector_fixedsize<Vector2d>());
+  CALL_SUBTEST(check_stdvector_fixedsize<Vector4f>());
+  CALL_SUBTEST(check_stdvector_fixedsize<Matrix4f>());
+  CALL_SUBTEST(check_stdvector_fixedsize<Matrix4d>());
+  
+}