Thank you for the report.  There does seem to be a regression in the 3.3 version of IDLE.  Using the OS X version of bin/idle3.3 and selecting menu item File -> Path Browser results in the following exception:

Exception in Tkinter callback
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.3/lib/python3.3/tkinter/__init__.py", line 1442, in __call__
    return self.func(*args)
  File "/Library/Frameworks/Python.framework/Versions/3.3/lib/python3.3/idlelib/TreeWidget.py", line 131, in expand
    self.update()
  File "/Library/Frameworks/Python.framework/Versions/3.3/lib/python3.3/idlelib/TreeWidget.py", line 164, in update
    self.parent.update()
  File "/Library/Frameworks/Python.framework/Versions/3.3/lib/python3.3/idlelib/TreeWidget.py", line 170, in update
    self.draw(7, 2)
  File "/Library/Frameworks/Python.framework/Versions/3.3/lib/python3.3/idlelib/TreeWidget.py", line 197, in draw
    cy = child.draw(cx, cy)
  File "/Library/Frameworks/Python.framework/Versions/3.3/lib/python3.3/idlelib/TreeWidget.py", line 184, in draw
    sublist = self.item._GetSubList()
  File "/Library/Frameworks/Python.framework/Versions/3.3/lib/python3.3/idlelib/TreeWidget.py", line 338, in _GetSubList
    sublist = self.GetSubList()
  File "/Library/Frameworks/Python.framework/Versions/3.3/lib/python3.3/idlelib/PathBrowser.py", line 61, in GetSubList
    for nn, name in self.listmodules(names):
  File "/Library/Frameworks/Python.framework/Versions/3.3/lib/python3.3/idlelib/PathBrowser.py", line 78, in listmodules
    for suff, mode, flag in suffixes:
ValueError: too many values to unpack (expected 3)