Tested with mixed results. I did the following:
* Booted a Hardy Live CD (in vbox), installed and launched oem-config
* Selected London from the tz map -- BUT I was offered a UK keyboard, so I cannot confirm the original problem
* Enabled proposed, updated oem-config (and ubiquity for good measure)
* Launched sudo oem-config from the terminal and selected London from the tz map again
* ==> Was offered a UK keyboard layout
Tested with mixed results. I did the following:
* Booted a Hardy Live CD (in vbox), installed and launched oem-config
* Selected London from the tz map -- BUT I was offered a UK keyboard, so I cannot confirm the original problem
* Enabled proposed, updated oem-config (and ubiquity for good measure)
* Launched sudo oem-config from the terminal and selected London from the tz map again
* ==> Was offered a UK keyboard layout