Bug report mtl library, sparse matrices

Dear Sirs,
Experimenting with sparse matrices on mtl I recently found the following
strange behavior, which seems to be a bug.

The c++ program code:
-------------------------------------------------------------------------------------
#include <iostream.h>
#include <mtl/matrix.h>
#include <mtl/mtl.h>
#include <mtl/utils.h>
#include <mtl/sparse1D.h>


using namespace mtl;
typedef matrix<double, rectangle<>, array< linked_list > , 
row_major>::type
theMatrix;

main(){
 
  theMatrix  whatIsTheMatrix(2, 2);

  whatIsTheMatrix(0,1)=1;

  print_all_matrix(whatIsTheMatrix);

  for(theMatrix::iterator theRow = whatIsTheMatrix.begin(); 
      theRow != whatIsTheMatrix.end();
      ++theRow)
     for(theMatrix::OneD::iterator theElt =(*theRow).begin();
         theElt != (*theRow).end();
         ++theElt)
       cout << *theElt<<endl;cout.flush();
  
}
-------------------------------------------------------------------------------------
The output of the complied program was the following:
BASH sparseTest
2x2
[
[0,0],
[0,0]
]
BASH
-------------------------------------------------------------------------------------
My quick fix for this problem is to change 
	 static inline bool notequal(const self& x, const self& y) 
of
	 template <class Cat> struct choose

at line 67 of sparse_iterator.h as follows:
-------------------------------------------------------------------------------------
    template <class self>
    static inline bool  self& x, const self& y) {

      //AD changed from 
      // return x.pos != y.pos;
      return x.iter != y.iter; 
    }
-------------------------------------------------------------------------------------
As far as I understand the code of mtl, x.pos and y.pos are always zero
in this case.
Hence for loops (as above or used in operator[](int) const of sparse1D)
terminate too early (i.e. immediately). 

After fixing notequal, the expected result is obtained:
-------------------------------------------------------------------------------------
BASH sparseTest
2x2
[
[0,1],
[0,0]
]
1
BASH
-------------------------------------------------------------------------------------

Is the bug already knows to you? Is this the best way to fix the
problem? (My changes may also interfere other mtl matrix types.)

I'm using mtl-2.1.2-21 on linux with gcc version 2.95.2 19991024.

Sincerely yours
  Alexander Dreyer

PS: Since my PhD-Thesis will also be about solving sparse systems, I
would be interested to know if there are any sparse solvers implemented
yet.

-- 
 / Alexander Dreyer, Dipl.-Math. - Abteilung Adaptive Systeme        \
/  Fraunhofer Institut fuer Techno- und Wirtschaftsmathematik (ITWM)  \
\  Gottlieb-Daimler-Strasse, Geb. 7^2=49/313  D-67663 Kaiserslautern  /
 \ http://www.itwm.fhg.de    Tel.:(0631)205-2851  Fax:(0631)205-4139 /
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