The XL models have a protection for the computer voices, if the device is not using the original NC they tend to stay silent.
But if I'm not mistaken your device should already use the 9.430 - does Home offer you any computer voices at all?
You can try
[Please Register or Login to download file] 9.430 I tried to create for the XL and 32mb models.
Use a setup with installed computer voice (preferable Kate) and overwrite with the content of my archive.
Check if the computer voice is working, if not use the skin chooser in the menu to select a different emulation - a double tap in the center confirms the selection and reboots the device.
If that still does not give you computervoices we can try a different way, but report back first.