abrt version: 1.1.18
architecture: x86_64
cmdline: python /usr/bin/meld
component: meld
executable: /usr/bin/meld
kernel: 2.6.35.11-83.fc14.x86_64
package: meld-1.5.1-1.fc14
reason: tree.py:111:value_path:TypeError: iter must be a GtkTreeIter
release: Fedora release 14 (Laughlin)
time: 1305304253
uid: 501

backtrace
-----
tree.py:111:value_path:TypeError: iter must be a GtkTreeIter

Traceback (most recent call last):
  File "/usr/share/meld/meld/vcview.py", line 422, in on_button_flatten_toggled
    self.refresh()
  File "/usr/share/meld/meld/vcview.py", line 583, in refresh
    self.set_location( self.model.value_path( self.model.get_iter_root(), 0 ) )
  File "/usr/share/meld/meld/tree.py", line 111, in value_path
    return self.get_value(it, self.column_index(COL_PATH, pane))
TypeError: iter must be a GtkTreeIter

Local variables in innermost frame:
self: <VcTreeStore object at 0x111fe10 (GtkTreeStore at 0xf11c20)>
it: None
pane: 0

How to reproduce
-----
1.Tried to scan a source tree for changes
2.
3.