I have recently setup Ubuntu ldap client authentication on karmic and lucid desktop clients and the ldap server is running on an 10.04 LTS server and this is the link I followed for client setup and probably this also works for 11.04. I could able to login to clients with the ldap user accounts and also, on the clients I used an entry session required pam_mkhomedir.so umask=0022 skel=/etc/skel in pam.d/common-session to automatically create the home directory on client computers when the user logs in for the first time. I guess there would be a way to synchronize the home directory from Client to Server and vice-versa so that users have their documents on which ever the client they login to.
I shared ldaphome at the server(192.168.1.2). Now the problem is I have /home as a separate partition on client and I unmounted it in fstab and mounted it with ldaphome which you could see in autofs config. When I try to login with ldap, after successful authentication, it again takes to the login screen. When I stop autofs service, it normally logs in creating the home directory as I used session required pam_mkhomedir.so umask=0022 in pam.d/common-session.
When I try to login for the first time with any new ldap account it gives the following error:
Creating directory '/home/user3'. Unable to create and initialize directory '/home/user3'. No directory, logging in with HOME=/