DParser: Unresolved Ambiguity

Question

I have a large grammar written for DParser format and using the Python binding. When I parse a code using this grammar, I get the following exception but with different symbols depending on what code I pass to it. But the ambiguous symbols are always the same non_terminal. How do I find out what the ambiguity is?

Traceback (most recent call last):
  File "parser.py", line 2030, in ambiguity
    raise dparser.AmbiguityException("\n\nUnresolved ambiguity!  Symbols:\n  " + '\n'.join([node.symbol for node in nodes]))
dparser.AmbiguityException:

Unresolved ambiguity!  Symbols:
  non_terminal
  non_terminal

Any hints or ideas would be appreciated.