Rebinding Tab key was inserting 'tab' instead of 'Tab'. Bug 1179168.
diff --git a/Lib/idlelib/keybindingDialog.py b/Lib/idlelib/keybindingDialog.py
index 26d6ad1..aff9cac 100644
--- a/Lib/idlelib/keybindingDialog.py
+++ b/Lib/idlelib/keybindingDialog.py
@@ -202,7 +202,7 @@
':':'colon',',':'comma','.':'period','<':'less','>':'greater',
'/':'slash','?':'question','Page Up':'Prior','Page Down':'Next',
'Left Arrow':'Left','Right Arrow':'Right','Up Arrow':'Up',
- 'Down Arrow': 'Down', 'Tab':'tab'}
+ 'Down Arrow': 'Down', 'Tab':'Tab'}
if key in translateDict.keys():
key = translateDict[key]
if 'Shift' in modifiers and key in string.ascii_lowercase: