Created attachment 196639 [details]
test script

Steps to reproduce:

1. Launch the test script in a terminal
2. Get into gnome-terminal's 'profile preferences' dialog
3. Tab amongst the widgets on the 'general' notebook page

Expected results: All widgets would report the associated keybinding/keystroke

Actual results: All widgets but the combobox do:

[text | ] has keybinding: <Alt>p
[check box | Use the system fixed width font] has keybinding: <Alt>u
[check box | Allow bold text] has keybinding: <Alt>a
[check box | Show menubar by default in new terminals] has keybinding: <Alt>m
[check box | Terminal bell] has keybinding: <Alt>b
[combo box | Block] has keybinding:      <----
[text | ] has keybinding: <Alt>w
[check box | Use custom default terminal size] has keybinding: <Alt>z
[push button | Help] has keybinding: <Alt>h
[push button | Close] has keybinding: <Alt>c

The 'press' accessible action is present; just the keystroke has gone missing.