I also get the message for several projects. For example, Pyajam:

$ pythoscope -t nose -i
INFO: Inspecting module __init__.py.
INFO: Inspecting module pyajam.py.
ERROR: Oops, it seems that an internal Pythoscope error occurred. Please file a bug report at https://bugs.launchpad.net/pythoscope

Traceback (most recent call last):
  File "/home/lstep/workspace/GIT/PYAJAM/bin/pythoscope", line 8, in <module>
    load_entry_point('pythoscope==0.4.3', 'console_scripts', 'pythoscope')()
  File "/home/lstep/workspace/GIT/PYAJAM/lib/python2.7/site-packages/pythoscope/__init__.py", line 184, in main
    init_project(project_path)
  File "/home/lstep/workspace/GIT/PYAJAM/lib/python2.7/site-packages/pythoscope/__init__.py", line 112, in init_project
    inspect_project_statically(project)
  File "/home/lstep/workspace/GIT/PYAJAM/lib/python2.7/site-packages/pythoscope/inspector/__init__.py", line 55, in inspect_project_statically
    return add_and_update_modules(project) + \
  File "/home/lstep/workspace/GIT/PYAJAM/lib/python2.7/site-packages/pythoscope/inspector/__init__.py", line 37, in add_and_update_modules
    static.inspect_module(project, modpath)
  File "/home/lstep/workspace/GIT/PYAJAM/lib/python2.7/site-packages/pythoscope/inspector/static.py", line 130, in inspect_module
    return inspect_code(project, path, read_file_contents(path))
  File "/home/lstep/workspace/GIT/PYAJAM/lib/python2.7/site-packages/pythoscope/inspector/static.py", line 139, in inspect_code
    visitor = descend(tree, ModuleVisitor)
  File "/home/lstep/workspace/GIT/PYAJAM/lib/python2.7/site-packages/pythoscope/astvisitor.py", line 20, in descend
    visitor.visit(tree)
  File "/home/lstep/workspace/GIT/PYAJAM/lib/python2.7/site-packages/pythoscope/astvisitor.py", line 155, in visit
    self.visit_node(tree)
  File "/home/lstep/workspace/GIT/PYAJAM/lib/python2.7/site-packages/pythoscope/astvisitor.py", line 169, in visit_node
    getattr(self, method)(results)
  File "/home/lstep/workspace/GIT/PYAJAM/lib/python2.7/site-packages/pythoscope/astvisitor.py", line 191, in _visit_all
    self.visit(results['nodes'])
  File "/home/lstep/workspace/GIT/PYAJAM/lib/python2.7/site-packages/pythoscope/astvisitor.py", line 158, in visit
    self.visit(subtree)
  File "/home/lstep/workspace/GIT/PYAJAM/lib/python2.7/site-packages/pythoscope/astvisitor.py", line 155, in visit
    self.visit_node(tree)
  File "/home/lstep/workspace/GIT/PYAJAM/lib/python2.7/site-packages/pythoscope/astvisitor.py", line 169, in visit_node
    getattr(self, method)(results)
  File "/home/lstep/workspace/GIT/PYAJAM/lib/python2.7/site-packages/pythoscope/astvisitor.py", line 196, in _visit_class
    body=results['body'])
  File "/home/lstep/workspace/GIT/PYAJAM/lib/python2.7/site-packages/pythoscope/inspector/static.py", line 91, in visit_class
    methods = [create_definition(n, a, c, Method) for (n, a, c) in visitor.methods]
  File "/home/lstep/workspace/GIT/PYAJAM/lib/python2.7/site-packages/pythoscope/inspector/static.py", line 74, in create_definition
    is_generator=is_generator_definition(code))
  File "/home/lstep/workspace/GIT/PYAJAM/lib/python2.7/site-packages/pythoscope/inspector/static.py", line 66, in is_generator_definition
    return is_generator_code(function_code_from_definition(definition))
  File "/home/lstep/workspace/GIT/PYAJAM/lib/python2.7/site-packages/pythoscope/inspector/static.py", line 52, in function_code_from_definition
    consts = compile_without_warnings(unindent(str(definition))).co_consts
  File "/usr/lib/python2.7/lib2to3/pytree.py", line 237, in __str__
    return unicode(self).encode("ascii")
  File "/usr/lib/python2.7/lib2to3/pytree.py", line 280, in __unicode__
    return u"".join(map(unicode, self.children))
  File "/usr/lib/python2.7/lib2to3/pytree.py", line 280, in __unicode__
    return u"".join(map(unicode, self.children))
  File "/usr/lib/python2.7/lib2to3/pytree.py", line 280, in __unicode__
    return u"".join(map(unicode, self.children))
  File "/usr/lib/python2.7/lib2to3/pytree.py", line 280, in __unicode__
    return u"".join(map(unicode, self.children))
  File "/usr/lib/python2.7/lib2to3/pytree.py", line 391, in __unicode__
    return self.prefix + unicode(self.value)
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc2 in position 4: ordinal not in range(128)

Here attached is the pyajam.py file (or you can get it on https://github.com/lstep/PyAjam )