xcompmgr and KDE

i am using KDE CVS version 20040117 (or whatever)

Although using xcompmgr with other DE (plain such as afterstep, etc) works 
smoothly, using it with KDE will lock the xserver

xcompmgr outputs in a loop:

error 3 request 3 minor 0
error 9 request 138 minor 4
error 9 request 141 minor 1
error 3 request 20 minor 0
error 136 request 138 minor 7

and it will keep on giving the above untill i try to move a window.
At the first move attempt it will segfault and lock the xserver

I know that thing are still under heavy development but i don't get why i 
don't get the same behaviour with afterstep for example