ListBoxError scrolling to the bottom of the variables view

I got this scrolling to the bottom of the variables view

```
---------------------------------------------------------------------------
ListBoxError Traceback (most recent call last)
in ()
----> 1 build_BDD(l)

/Users/aaronmeurer/Documents/Continuum/conda/conda/logic.py in build_BDD(linear, sum, material_left)
200 clauses += new_clauses
201 ret, new_clauses = ITE(LA, hi, lo)
--> 202 clauses += new_clauses
203
204 return ret, new_clauses

/Users/aaronmeurer/Documents/Continuum/conda/conda/logic.py in build_BDD(linear, sum, material_left)
200 clauses += new_clauses
201 ret, new_clauses = ITE(LA, hi, lo)
--> 202 clauses += new_clauses
203
204 return ret, new_clauses

/Users/aaronmeurer/anaconda/lib/python3.3/bdb.py in trace_dispatch(self, frame, event, arg)
45 return # None
46 if event == 'line':
---> 47 return self.dispatch_line(frame)
48 if event == 'call':
49 return self.dispatch_call(frame, arg)

/Users/aaronmeurer/anaconda/lib/python3.3/bdb.py in dispatch_line(self, frame)
63 def dispatch_line(self, frame):
64 if self.stop_here(frame) or self.break_here(frame):
---> 65 self.user_line(frame)
66 if self.quitting: raise BdbQuit
67 return self.trace_dispatch

/Users/aaronmeurer/anaconda/lib/python3.3/site-packages/pudb/debugger.py in user_line(self, frame)
320 self.ui.update_breakpoints()
321
--> 322 self.interaction(frame)
323
324 def user_return(self, frame, return_value):

/Users/aaronmeurer/anaconda/lib/python3.3/site-packages/pudb/debugger.py in interaction(self, frame, exc_tuple, show_exc_dialog)
288
289 self.ui.call_with_ui(self.ui.interaction, exc_tuple,
--> 290 show_exc_dialog=show_exc_dialog)
291
292 def get_stack_situation_id(self):

/Users/aaronmeurer/anaconda/lib/python3.3/site-packages/pudb/debugger.py in call_with_ui(self, f, *args, **kwargs)
1834 self.show()
1835 try:
-> 1836 return f(*args, **kwargs)
1837 finally:
1838 self.hide()

/Users/aaronmeurer/anaconda/lib/python3.3/site-packages/pudb/debugger.py in interaction(self, exc_tuple, show_exc_dialog)
2012
2013 self.caption.set_text(caption)
-> 2014 self.event_loop()
2015
2016 def set_source_code_provider(self, source_code_provider, force_update=False):

/Users/aaronmeurer/anaconda/lib/python3.3/site-packages/pudb/debugger.py in event_loop(self, toplevel)
1978 self.size = self.screen.get_cols_rows()
1979 else:
-> 1980 toplevel.keypress(self.size, k)
1981
1982 return self.quit_event_loop

/Users/aaronmeurer/anaconda/lib/python3.3/site-packages/pudb/ui_tools.py in keypress(self, size, key)
81
82 if result is not None:
---> 83 result = self._w.keypress(size, key)
84
85 if result is not None and not self.is_preemptive:

/Users/aaronmeurer/anaconda/lib/python3.3/site-packages/urwid/container.py in keypress(self, size, key)
1101 if not self.body.selectable():
1102 return key
-> 1103 return self.body.keypress( (maxcol, remaining), key )
1104
1105

/Users/aaronmeurer/anaconda/lib/python3.3/site-packages/urwid/container.py in keypress(self, size, key)
2239 key = w.keypress((mc, self.rows(size, True)), key)
2240 else:
-> 2241 key = w.keypress((mc,) + size[1:], key)
2242
2243 if self._command_map[key] not in ('cursor left', 'cursor right'):

/Users/aaronmeurer/anaconda/lib/python3.3/site-packages/pudb/ui_tools.py in keypress(self, size, key)
81
82 if result is not None:
---> 83 result = self._w.keypress(size, key)
84
85 if result is not None and not self.is_preemptive:

/Users/aaronmeurer/anaconda/lib/python3.3/site-packages/urwid/container.py in keypress(self, size, key)
1558 if self.selectable():
1559 tsize = self.get_item_size(size, i, True, item_rows)
-> 1560 key = self.focus.keypress(tsize, key)
1561 if self._command_map[key] not in ('cursor up', 'cursor down'):
1562 return key

/Users/aaronmeurer/anaconda/lib/python3.3/site-packages/urwid/container.py in keypress(self, size, key)
1558 if self.selectable():
1559 tsize = self.get_item_size(size, i, True, item_rows)
-> 1560 key = self.focus.keypress(tsize, key)
1561 if self._command_map[key] not in ('cursor up', 'cursor down'):
1562 return key

/Users/aaronmeurer/anaconda/lib/python3.3/site-packages/pudb/ui_tools.py in keypress(self, size, key)
81
82 if result is not None:
---> 83 result = self._w.keypress(size, key)
84
85 if result is not None and not self.is_preemptive:

/Users/aaronmeurer/anaconda/lib/python3.3/site-packages/urwid/listbox.py in keypress(self, size, key)
997
998 if self._command_map[key] == CURSOR_DOWN:
--> 999 return actual_key(self._keypress_down((maxcol, maxrow)))
1000
1001 if self._command_map[key] == CURSOR_PAGE_UP:

/Users/aaronmeurer/anaconda/lib/python3.3/site-packages/urwid/listbox.py in _keypress_down(self, size)
1132 if widget is None:
1133 self.shift_focus((maxcol,maxrow),
-> 1134 row_offset-rows)
1135 return
1136 # FIXME: catch this bug in testcase

/Users/aaronmeurer/anaconda/lib/python3.3/site-packages/urwid/listbox.py in shift_focus(self, size, offset_inset)
778 tgt_rows = target.rows( (maxcol,), True )
779 if offset_inset + tgt_rows <= 0:
--> 780 raise ListBoxError("Invalid offset_inset: %r, only %r rows in target!" %(offset_inset, tgt_rows))
781 self.offset_rows = 0
782 self.inset_fraction = (-offset_inset,tgt_rows)

ListBoxError: Invalid offset_inset: -1, only 1 rows in target!
```

Here is my pudb.cfg:

``` cfg
[pudb]
breakpoints_height = 0.0267918337155
breakpoints_weight = 0.20971520000000005
current_stack_frame = bottom
custom_stringifier = ~/Documents/pudb/example-stringifier.py
custom_theme = ~/Documents/pudb/example-theme.py
display = auto
line_numbers = True
prompt_on_quit = True
seen_welcome = e019
shell = classic
sidebar_width = 0.390625
stack_height = 0.0368045127061
stack_weight = 0.16777216000000003
stringifier = str
theme = midnight
variables_height = 0.936403653578
variables_weight = 5.96046447753
wrap_variables = True
```

My terminal is 40 lines by 141 columns.