Can't select any desktop except unity

same here, fresh install of 12.10 i386. i have kde, lxde and xfce installed additionally and the greeter selector seems not to be responding: you can enter the menu by clicking on the ubuntu symbol but then selecting anything from the list does nothing at all and the menu list stays open. you can close it only by clicking the "<" icon, returning to the username box but the ubuntu symbol stays selected and upon login one gets unity. another annoyance is that the list of available desktop environments is truncated on screens with small resolutions (and it does not scroll up). it seems that the design did not anticipate to have so many choices...

the only solution for now is to switch to gdm or kdm...

Status changed to 'Confirmed' because the bug affects multiple users.

Same here after upgrade from 12.04. I may choose Unity only now.

This dumb little problem has an easy fix.
1. log on and you will see the list of possible desktop environments.
2. mouse click the one you want. Prior to Ubuntu 12.10, when you did this, the one you chose appeared in a rectangle, so you knew that when you gave your password, you knew you were logging onto what you wanted. Now for some reason, this doesn't happen. When you mouse click on what you want, nothing happens - the dropdown list stays as if you haven't selected anything. What you don't realize is that your selection has been noted, and off the screen there is an OK box waiting for your confirmation.
3. Press TAB twice, which highlights the OK box that you can't see.
4. Press ENTER
... and you are in!

Closing assumed fixed.