I have OpenSuSE 11.4 (x86_64) on three different machine on my network.
XDMCP running on all three, no firewalls.

Up thru KDE 4.6.x, I was able to start a remote session between machines by choosing Menu-Remote Login on the Greeter (GUI Login) screen.

When I updated to 4.7.1, this no longer works.
After selecting Menu-Remote Login, an expected panel opens in the middle of the screen listing the XDMCP clients available.
Moving the mouse into the panel (to select desired machine to connect to) causes the panel to disappear(crash?), returning me to the normal User/Password dialog.

Is this issue unique to SuSE?

Have you checked /var/log/kdm.log?

I have looked - nothing.
Is there a different log used by the Greeter/login process?

I'm not sure, I haven't noticed any greeter logs here. I also can't confirm if it happens on my machines, kde 4.7 is still in experimental branch, I think. Maybe somebody else can check it. By the way, does anything appear on tty1 or in /var/log/messages?

btw, do you use NIS in your setup? I've found this:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=625528

Nothing in /var/log/messages and nothing on vt1 (logged in as root) while attempting to start a remote session.

NIS - nope. NFS and Samba servers are running

I looked in kdmrc - kdm runs as root in this configuration. I have seen some posts related to recent shift to user=kdm, but not on SuSE.

Thanks for the suggestions

Since this might be segfault, you should probably fill a bug report somewhere. I'm not involved into KDE development, but you might try there

I just found a bug report on Ubuntu, same issue.
https://bugs.launchpad.net/ubuntu/+source/kde-workspace/+bug/872761

I entered a KDE Bug
Bug 283919 - KDM greeter remote login dialog crashes on mouseover

Now it'll take some time to get fixed and incorporated into your distribution, as a workaround I would suggest downgrading kdm (may not work at all) or configurig it to use other xdmcp browser (that should be possible, I think).

Thanks, I have vnc working just prefer the remote X at times.