pyROOT - viewing geometry

Hi ROOTers,

I was probably hit some TGeoMatrix creation error. Attached is a toy geometry file with some bricks, and the following macro works perfectly in "direct ROOT" (showing the geom, aligning the bricks, redrawing,
realigning, redrawing):

{
new TGeoManager();
gGeoManager->Import("lcontainers.root"); TGeoPhysicalNode *physnodes[6];
nentries=gGeoManager->GetListOfPhysicalNodes()->GetEntries(); for (Int_t i=0 ; i<nentries;i++)
{
cout << i << endl;
physnodes[i]=gGeoManager->GetPhysicalNode(i); }
TGeoVolume *top = gGeoManager->GetTopVolume(); top->Draw("ogl");
TGeoRotation *rot = new TGeoRotation();
TGeoCombiTrans *combi[6];
for (Int_t i=0 ; i<nentries;i++)
{
cout << i << endl;
combi[i] = new TGeoCombiTrans(0,500*i, 0, rot); }
for (Int_t i=0 ; i<nentries;i++)
{
physnodes[i].Align(combi[i]);
}
top->Draw("ogl");
}

yet a try to recreate the following using pyROOT fails with segfault:

import ROOT
g = ROOT.TGeoManager()
g = ROOT.gGeoManager.Import("lcontainers.root") rotation=ROOT.TGeoRotation()
corr=[]
vol = g.GetTopVolume()
vol.Draw("ogl")
for i in range(6):

    corr.append(ROOT.TGeoCombiTrans(0,500*i,0,rotation))     g.GetPhysicalNode(i).Align(corr[i])
vol.Draw("ogl")

Invoking Draw() on the top volume after aligning the contents yields: Info in <TGLSceneBase::RemoveViewer>: scene 'unnamed-1' not used - autodestructing.

• Break *** segmentation violation
  (no debugging symbols found)
  Using host libthread_db library "/lib/tls/i686/cmov/libthread_db.so.1". Attaching to program: /proc/16566/exe, process 16566 [Thread debugging using libthread_db enabled] [New Thread 0xb7de68c0 (LWP 16566)] [New Thread 0xb4f2bb90 (LWP 16574)]
  (no debugging symbols found)...done.
  (no debugging symbols found)...done.
  (no debugging symbols found)...done.
  (no debugging symbols found)...done.
  (no debugging symbols found)...done.
  (no debugging symbols found)...done.
  (no debugging symbols found)...done.
  (no debugging symbols found)...done.
  (no debugging symbols found)...done.
  (no debugging symbols found)...done.
  0xb7f93410 in __kernel_vsyscall () error detected on stdin The program is running. Quit anyway (and detach it)? (y or n) [answered Y; input not from terminal] Detaching from program: /proc/16566/exe, process 16566

Could you please check yourselves and/or point me my mistake ?

Regards
Michal