Error message upon PDB loading -- March 18, 2014 - 10:13

Hello,
I hope I do not bug you too often, but I keep receiving error messages. Here 
is one, upon loading a PDB file generated using Chimera, and no spins are 
loaded in the spin viewer. I am using 3.1.7.
Stefano

Internal relax PDB parser.
Opening the file '/Users/stefano/Desktop/13-BpUreE-NMR/Manuscript/Figure 6,7 
- Dynamics/relax/dimer_H.pdb' for reading.
Traceback (most recent call last):
  File "gui/interpreter.pyc", line 303, in run
  File "pipe_control/structure/main.pyc", line 722, in read_pdb
  File "lib/structure/internal/object.pyc", line 1813, in load_pdb
  File "lib/structure/internal/object.pyc", line 500, in _parse_pdb_ss
  File "lib/structure/pdb_read.pyc", line 1221, in sheet
IndexError: string index out of range
Exception in thread Thread-1:
Traceback (most recent call last):
  File "threading.pyc", line 808, in __bootstrap_inner
  File "gui/interpreter.pyc", line 323, in run
  File "status.pyc", line 369, in release
  File "status.pyc", line 413, in notify
  File "gui/analyses/auto_model_free.pyc", line 276, in activate
  File 
"/Applications/relax.app/Contents/Resources/lib/python2.7/wx/_core.py", line 
16769, in CallAfter
AssertionError: callableObj is not callable