Steps to reproduce:
1) Boot into quantal daily (either bare mental or KVM sdl with sound)
2) Wait until you hear drums
3) Press Ctrl+S to start the screen reader
4) Alt-Tab from Orca preferences window to the installer
5) Tab -> "Try ubuntu push button" Tab -> "Install ubuntu" Enter
6) "Con..." and orca goes silent.

Instead you should hear "Continue push button" and be able to tab around and hear the labels getting announced.

If orca is launched from the terminal the following messages appear. The text that "no longer exists" is the stuff currently displayed on the screen and should be read back to the user....

This bug blocks fixing other orca/screen reader bugs in ubiquity & testing a11y installation.

$ orca

** (orca:8823): WARNING **: Unable to open bus connection: Empty address ''

** (orca:8823): WARNING **: AT-SPI: Error in GetItems, sender=:1.24, error=Method "GetItems" with signature "" on interface "org.a11y.atspi.Cache" doesn't exist


** (orca:8823): WARNING **: Unable to open bus connection: Empty address ''

** (orca:8823): WARNING **: AT-SPI: Error in GetItems, sender=(null), error=Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.

** (orca:8823): WARNING **: AT-SPI: Error in GetItems, sender=:1.26, error=Method "GetItems" with signature "" on interface "org.a11y.atspi.Cache" doesn't exist

_toolkitForObject: [radio button | Connect to this network] no longer exists
_toolkitForObject: [check box | Use LVM with the new Ubuntu installation] no longer exists
_toolkitForObject: [check box | Encrypt the new Ubuntu installation for security] no longer exists
_toolkitForObject: [push button | Revert] no longer exists
_toolkitForObject: [push button | LVM...] no longer exists
_toolkitForObject: [push button | New Partition Table...] no longer exists
_toolkitForObject: [check box | Overwrite empty disk space] no longer exists
_toolkitForObject: [push button | Detect Keyboard Layout] no longer exists
_toolkitForObject: [radio button | Log in automatically] no longer exists
_toolkitForObject: [radio button | Require my password to log in] no longer exists
_toolkitForObject: [check box | Encrypt my home folder] no longer exists
_toolkitForObject: [DEAD] no longer exists
_toolkitForObject: [DEAD] no longer exists
_toolkitForObject: [DEAD] no longer exists
_toolkitForObject: [DEAD] no longer exists
_toolkitForObject: [frame | Install] no longer exists
_toolkitForObject: [push button | Quit] no longer exists
_toolkitForObject: [push button | Back] no longer exists
_toolkitForObject: [push button | Continue] no longer exists
_toolkitForObject: [push button | Continue] no longer exists
_toolkitForObject: [label | that you are plugged in to a power source] no longer exists
_toolkitForObject: [label | that you are plugged in to a power source] no longer exists
_toolkitForObject: [label | is plugged in to a power source] no longer exists
_toolkitForObject: [label | that you are connected to the Internet] no longer exists
_toolkitForObject: [label | that you are connected to the Internet] no longer exists
_toolkitForObject: [label | is connected to the Internet] no longer exists
_toolkitForObject: [label | ${RELEASE} uses third-party software to play Flash, MP3 and other media, and to work with some graphics and wi-fi hardware. Some of this software is proprietary. The software is subject to license terms included with its documentation.] no longer exists
_toolkitForObject: [label | ${RELEASE} uses third-party software to play Flash, MP3 and other media, and to work with some graphics and wi-fi hardware. Some of this software is proprietary. The software is subject to license terms included with its documentation.] no longer exists
_toolkitForObject: [label | Ubuntu uses third-party software to play Flash, MP3 and other media, and to work with some graphics and wi-fi hardware. Some of this software is proprietary. The software is subject to license terms included with its documentation.] no longer exists
_toolkitForObject: [check box | Display password] no longer exists
_toolkitForObject: [push button | ] no longer exists
_toolkitForObject: [push button | ] no longer exists

** (orca:8823): WARNING **: AT-SPI: AddAccessible with unknown signature ((so)(so)(so)a(so)assuau)


** (orca:8823): WARNING **: AT-SPI: AddAccessible with unknown signature ((so)(so)(so)a(so)assuau)


** (orca:8823): WARNING **: AT-SPI: AddAccessible with unknown signature ((so)(so)(so)a(so)assuau)


** (orca:8823): WARNING **: AT-SPI: AddAccessible with unknown signature ((so)(so)(so)a(so)assuau)