[orca] Fix a traceback in the braille monitor

[Joanmarie Diggs <joanied src gnome org>]

commit 4012251669eaee6a041573f6811c8657e4f7d0c6
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Wed Jan 9 13:42:20 2013 -0500

    Fix a traceback in the braille monitor

 src/orca/brlmon.py |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/orca/brlmon.py b/src/orca/brlmon.py
index ec76392..d9054a5 100644
--- a/src/orca/brlmon.py
+++ b/src/orca/brlmon.py
@@ -218,6 +218,6 @@ class BrlMon(Gtk.Window):
             isCursorCell = i == cursorCell - 1
             try:
                 cellMask = mask[i]
-            except IndexError:
+            except (IndexError, TypeError):
                 cellMask = None
             self.cells[i].display(string[i], cellMask, isCursorCell)