I had this problem that Xephyr kept crashing when I clicked an editable area in the maemo sdk.
This is the bug in question: http://bugs.freedesktop.org/show_bug.cgi?id=21591

The latest version of Zephyr 1.6.3 has this fixed. And I found it in the ubuntu repo here:
http://archive.ubuntu.com/ubuntu/poo...untu6_i386.deb

It's part of the karmic release.

All I did was remove xephyr, temporarily add
deb http://archive.ubuntu.com/ubuntu/ karmic main
to sources.list
then apt-get update and reinstall xephyr, to get all the dependencies updated.
Then I removed the karmic repository from sources.list again.

This is probably not the way it's supposed to be done, but it worked for me. I'm not a linux guru so I have no idea what the correct way is to go about these things.

I use Linux Mint Gloria that is based on ubuntu jaunty.

Anywa I was annoyed that there was no good explanation anywhere on how to solve this, so I thought I'd make my solution public.

The gurus can add a proper way to do it below, thank you.