It also affects me.
A simple workaround is to install the lightdm package from Oneiric:
http://packages.ubuntu.com/oneiric/lightdm
I downloaded it from that page and installed manually using dpkg. It is seems to work well.
In order to avoid an update of the package to the Precise version you need to put lightdm on hold:
https://help.ubuntu.com/community/PinningHowto#Introduction_to_Holding_Packages
Note that this is not an ideal solution as you will not receive security updates for this package. By putting it on hold you are assuming manual control over it, so it is your responsibility to update it manually when needed.
It also affects me.
A simple workaround is to install the lightdm package from Oneiric:
http:// packages. ubuntu. com/oneiric/ lightdm
I downloaded it from that page and installed manually using dpkg. It is seems to work well.
In order to avoid an update of the package to the Precise version you need to put lightdm on hold:
https:/ /help.ubuntu. com/community/ PinningHowto# Introduction_ to_Holding_ Packages
Note that this is not an ideal solution as you will not receive security updates for this package. By putting it on hold you are assuming manual control over it, so it is your responsibility to update it manually when needed.