xen-pae and headerfiles

[Frank <josephbeuys@gmx.de>]

By default the xen-pae version is installed but I don't need it because 
  the maschine has only 512MB. Should I still use pae and how could I 
get rid of pae packages?

Also by default no xen header files are installed. Are they optional or 
what for xen uses it?

etch01:~# apt-get install xen-linux-system-2.6.18-4-xen-686 xen-tools
Reading package lists... Done
Building dependency tree... Done
The following extra packages will be installed:
  debootstrap iproute libatm1 libtext-template-perl
  linux-image-2.6.18-4-xen-686 linux-modules-2.6.18-4-xen-686 python
  python-central python-minimal python2.4 python2.4-minimal wget
  xen-hypervisor-3.0.3-1-i386-pae xen-utils-3.0.3-1 xen-utils-common
Suggested packages:
  linux-doc-2.6.18 python-doc python-tk python-profiler python2.4-doc
  xen-docs-3.0
Recommended packages:
  iproute-doc libc6-xen xen-hypervisor reiserfsprogs xfsprogs rpmstrap
  perl-doc bridge-utils xen-hypervisor-3.0.3-1
The following NEW packages will be installed:
  debootstrap iproute libatm1 libtext-template-perl
  linux-image-2.6.18-4-xen-686 linux-modules-2.6.18-4-xen-686 python
  python-central python-minimal python2.4 python2.4-minimal wget
  xen-hypervisor-3.0.3-1-i386-pae xen-linux-system-2.6.18-4-xen-686 
xen-tools
  xen-utils-3.0.3-1 xen-utils-common
0 upgraded, 17 newly installed, 0 to remove and 1 not upgraded.
Need to get 21.4MB of archives.
After unpacking 66.0MB of additional disk space will be used.
Do you want to continue [Y/n]?