Alex,

|  We have noticed severe problems with X11 under SL 4.0 here. The problems 
|mostly occur when we open windows on a remote machine and display them on a 
|machine running SL 4.0. The remote machine can be both another 4.0 machine or an 
|SL 3.03 machine, the problems are the same, suggesting it is a feature of the 
|X11 server. I note that the X11 system is now xorg-x11, not xfree86 as before, 
|and I can't help but suspect this is the culprit. Here is a list of the problems 
|we have encountered:

I ran SL4 at home for a week.  I had problems with
nvidia's drivers (latest and 7174), but when I ran in
vesa or with the nv driver, X worked just fine, including
lots of ssh'ing.  (I saw identical driver problems on RH9
and SL302, everything but RH8!)

I don't use emacs, but I certainly didn't see anything
hang on window closings.  So perhaps you have a driver
problem as well.  FWIW, I saw this with an ABIT KG7
board and a Jaton MX400 Twin.

I didn't try an "xhost +", but did use "xhost +foo"
with no problems.

FWIW.

-Miles