ee -> ttaa at NLO fails

Dear all,

MG5_aMC fails for the NLO computation of e+ e- > ttaa because the poles do not cancel. At LO, the integration works fine.
I use the same setup as in
https://answers.launchpad.net/mg5amcnlo/+question/503117 and
https://answers.launchpad.net/mg5amcnlo/+question/447599.

Especially, the top width is set to zero.

The debug.log is

launch auto
Traceback (most recent call last):
  File "/home/cweiss/Software/Madgraph/MG5_aMC_v2_5_2/madgraph/interface/extended_cmd.py", line 1415, in onecmd
    return self.onecmd_orig(line, **opt)
  File "/home/cweiss/Software/Madgraph/MG5_aMC_v2_5_2/madgraph/interface/extended_cmd.py", line 1369, in onecmd_orig
    return func(arg, **opt)
  File "/home/cweiss/Software/Madgraph/MG5_aMC_v2_5_2/madgraph/interface/amcatnlo_run_interface.py", line 1226, in do_launch
    self.compile(mode, options)
  File "/home/cweiss/Software/Madgraph/MG5_aMC_v2_5_2/madgraph/interface/amcatnlo_run_interface.py", line 4712, in compile
    self.check_tests(test, this_dir)
  File "/home/cweiss/Software/Madgraph/MG5_aMC_v2_5_2/madgraph/interface/amcatnlo_run_interface.py", line 4725, in check_tests
    return self.parse_check_poles_log(pjoin(dir, '%s.log' % test))
  File "/home/cweiss/Software/Madgraph/MG5_aMC_v2_5_2/madgraph/interface/amcatnlo_run_interface.py", line 4760, in parse_check_poles_log
    raise aMCatNLOError('Poles do not cancel, run cannot continue')
aMCatNLOError: Poles do not cancel, run cannot continue
Value of current Options:
              text_editor : None
      notification_center : True
                    pjfry : None
       cluster_local_path : None
       group_subprocesses : Auto
ignore_six_quark_processes : False
    loop_optimized_output : True
    cluster_status_update : (600, 30)
               hepmc_path : None
                  collier : /home/cweiss/Software/Madgraph/MG5_aMC_v2_5_2/HEPTools/lib
              auto_update : 7
             pythia8_path : None
                hwpp_path : None
low_mem_multicore_nlo_generation : False
                    golem : None
          pythia-pgs_path : None
                  td_path : None
             delphes_path : None
              thepeg_path : None
             cluster_type : condor
        madanalysis5_path : None
      exrootanalysis_path : None
                      OLP : MadLoop
                 applgrid : applgrid-config
               eps_viewer : None
                  fastjet : None
                 run_mode : 2
              web_browser : None
   automatic_html_opening : False
        cluster_temp_path : None
             cluster_size : 100
            cluster_queue : None
             syscalc_path : None
         madanalysis_path : None
                   lhapdf : lhapdf-config
             stdout_level : 20
                  nb_core : 4
            f2py_compiler : None
                    ninja : /home/cweiss/Software/Madgraph/MG5_aMC_v2_5_2/HEPTools/lib
                  amcfast : amcfast-config
       cluster_retry_wait : 300
      output_dependencies : external
         fortran_compiler : None
mg5amc_py8_interface_path : /home/cweiss/Software/Madgraph/MG5_aMC_v2_5_2/HEPTools/MG5aMC_PY8_interface
         loop_color_flows : False
                  samurai : None
         cluster_nb_retry : 1
                 mg5_path : /home/cweiss/Software/Madgraph/MG5_aMC_v2_5_2
                  timeout : 60
                    gauge : unitary
      complex_mass_scheme : False
             cpp_compiler : None
   max_npoint_for_channel : 0

Best,
Christian