upgrade broken (Testing) for 10 days - libxrender

[Uwe Dippel <udippel@uniten.edu.my>]

I searched the archives and Google, without success.
The subject says it. I automatically do a daily 
apt-get update
apt-get upgrade

Some 10 to 14 days back there was a problem coming in:

# apt-get upgrade
Reading Package Lists... Done
Building Dependency Tree... Done
You might want to run `apt-get -f install' to correct these.
The following packages have unmet dependencies:
  libxaw7-dev: Depends: x-dev but it is not installed
               Depends: libxmu-dev but it is not installed
               Depends: libxt-dev but it is not installed
               Depends: libsm-dev but it is not installed
               Depends: libice-dev but it is not installed
               Depends: libxext-dev but it is not installed
               Depends: libx11-dev but it is not installed
               Depends: libxpm-dev but it is not installed
  libxrender-dev: Depends: libxrender1 (= 0.8.3-5) but 0.8.3-7 is installed
E: Unmet dependencies. Try using -f.

I tried -f, but to no avail:

apt-get -f install
[... many lines removed ...]
Unpacking libxpm-dev (from .../libxpm-dev_4.3.0-7_i386.deb) ...
dpkg: error processing /var/cache/apt/archives/libxpm-dev_4.3.0-7_i386.deb (--unpack):
 trying to overwrite `/usr/X11R6/include/X11/xpm.h', which is also in package xlibs-dev
dpkg-deb: subprocess paste killed by signal (Broken pipe)
Preparing to replace libxrender-dev 0.8.3-5 (using .../libxrender-dev_0.8.3-7_i386.deb) ...
Unpacking replacement libxrender-dev ...
dpkg: error processing /var/cache/apt/archives/libxrender-dev_0.8.3-7_i386.deb (--unpack):
 trying to overwrite `/usr/X11R6/include/X11/extensions/Xrender.h', which is also in package xlibs-dev
dpkg-deb: subprocess paste killed by signal (Broken pipe)
Errors were encountered while processing:
 /var/cache/apt/archives/libice6_4.3.0-7_i386.deb
 /var/cache/apt/archives/libsm6_4.3.0-7_i386.deb
 /var/cache/apt/archives/libx11-6_4.3.0-7_i386.deb
 /var/cache/apt/archives/libxext6_4.3.0-7_i386.deb
 /var/cache/apt/archives/x-dev_4.3.0-7_all.deb
 /var/cache/apt/archives/libxt6_4.3.0-7_i386.deb
 /var/cache/apt/archives/libxmu6_4.3.0-7_i386.deb
 /var/cache/apt/archives/libx11-dev_4.3.0-7_i386.deb
 /var/cache/apt/archives/libice-dev_4.3.0-7_i386.deb
 /var/cache/apt/archives/libsm-dev_4.3.0-7_i386.deb
 /var/cache/apt/archives/libxt-dev_4.3.0-7_i386.deb
 /var/cache/apt/archives/libxext-dev_4.3.0-7_i386.deb
 /var/cache/apt/archives/libxmu-dev_4.3.0-7_i386.deb
 /var/cache/apt/archives/libxpm4_4.3.0-7_i386.deb
 /var/cache/apt/archives/libxpm-dev_4.3.0-7_i386.deb
 /var/cache/apt/archives/libxrender-dev_0.8.3-7_i386.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)

Is this known ? (Could not find anything in Debian-Bugs)
How would I go back to an upgradable Testing ?

Thanks for any hint,

Uwe