Newton goes mad

'Extern
'include Newton took from here: 
'http://www.blitzbasic.com/Community/posts.php?topic=69650#779390
'End Extern

Local nWorld:Byte Ptr=NewtonCreate(Null,Null)
Local collision:Byte Ptr= NewtonCreateSphere (nWorld, 2,2,2,Null);

Local ribidBodyBox:Byte Ptr = NewtonCreateBody (nWorld, collision);

NewtonReleaseCollision (nWorld, collision);

Local gravitation:Float[]=[0.0,2.0,0.0]
Local pos:Float[16]
pos[0]=1
pos[5]=1
pos[10]=1
pos[15]=1


Local posi:Byte Ptr=Varptr pos[0]

NewtonBodySetMassMatrix (ribidBodyBox, 1.0, 5.0, 1.0, 5.0);
NewtonBodySetMatrix(ribidBodyBox,Varptr pos[0])
NewtonBodySetOmega (ribidBodyBox, Varptr gravitation[0]);

Local rendertime:Float=1
Repeat
   Local lasttime:Float=MilliSecs()
   NewtonUpdate(nWorld, 5.0);
   Local matrix:Float[4,4]
      NewtonBodyGetMatrix(ribidBodyBox, Varptr matrix[0,0])
   DebugLog matrix[0,0]
   rendertime=MilliSecs()-lasttime
Until KeyHit(KEY_ESCAPE)

NewtonDestroy (nWorld)
End

DebugLog matrix[0,0]+" "+ matrix[1,0] 'doesnt work
DebugLog matrix[0,0] 'works
DebugLog matrix[1,0] 'works