Singular Matrix

General Discussion
1 
load "msh3"

////////////////////////////////////////////////////////////////////////////////////
//Problem Variables
////////////////////////////////////////////////////////////////////////////////////
real EI=1.2;
real p=4.0;

////////////////////////////////////////////////////////////////////////////////////
//Meshing
////////////////////////////////////////////////////////////////////////////////////
meshL Msh = Sline(40,[x,1,x*0.1]);

////////////////////////////////////////////////////////////////////////////////////
//Solving
////////////////////////////////////////////////////////////////////////////////////
//Defining the Finite Element Simulation
fespace Ob(Msh, P2);
//Defining all variables within the FEM Simulation
Ob u, w;

//Implementing the PDE
solve OneDBeam(u, w)
    = int1d(Msh)(
        dxx(w)*EI*dxx(u)
    )
    - int1d(Msh)(
        w*p
    )
    + on(1, u=2);

////////////////////////////////////////////////////////////////////////////////////
//Plotting
////////////////////////////////////////////////////////////////////////////////////
//Show the Mesh, press enter to move to next plot
plot(Msh, wait=true);
plot(Msh, u, wait=true);

////////////////////////////////////////////////////////////////////////////////////
//End
////////////////////////////////////////////////////////////////////////////////////

I ran it on a linux machine and this is the output:

  39 : ////////////////////////////////////////////////////////////////////////////////////
   40 : //End
   41 : ////////////////////////////////////////////////////////////////////////////////////
   42 :  sizestack + 1024 =1752  ( 728 )

  -- Build Nodes/DF on mesh :   n.v. 41, n. elmt. 40, n b. elmt. 2
     nb of Nodes 81    nb of DoF   81  DFon=1100
  -- FESpace: Nb of Nodes 81 Nb of DoF 81
1 UMFPACK WARNING singular matrix 
1 UMFPACK WARNING singular matrix 
  -- Solve : 
          min inf  max inf
  Plot::  Sorry no ps version for this type of plot 55
  Plot::  Sorry no ps version for this type of plot 55
  Plot::  Sorry no ps version for this type of plot 14
times: compile 0.004249s, execution 0.000558s,  mpirank:0
 CodeAlloc : nb ptr  3830,  size :515384 mpirank: 0
Ok: Normal End

I am trying to solve a simple 1d beam problem wherein I have something like a weak form:
integral w’’ * EI * u’’ dx - integral wp dx
wherein E*I is flexural stiffness, w is weight function and p is distributed load.

I think that there is a problem with the matrix beign singular but I dont really see what I am missing from a problem definition standpoint. I hope you guys can help me. Thanks alot