package mythbuntu-gdm-theme (not installed) failed to install/upgrade

Binary package hint: mythbuntu-gdm-theme

I installed ubuntu 10.04 beta 1 from my usb device (created with the tool in ubuntu 9.10) and done an update.
while installing the packages, the error occured

ProblemType: Package
DistroRelease: Ubuntu 10.04
Package: mythbuntu-gdm-theme (not installed)
ProcVersionSignature: Ubuntu 2.6.32-16.25-generic
Uname: Linux 2.6.32-16-generic i686
Architecture: i386
Date: Sun Mar 28 14:40:38 2010
ErrorMessage: Versuche, »/usr/share/images/xsplash/logo_small.png« zu überschreiben, welches auch in Paket ubuntu-xsplash-artwork 0:0.8.5-0ubuntu1 ist
InstallationMedia: Ubuntu 10.04 "Lucid Lynx" - Beta i386 (20100318)
SourcePackage: mythbuntu-gdm-theme
Title: package mythbuntu-gdm-theme (not installed) failed to install/upgrade: Versuche, »/usr/share/images/xsplash/logo_small.png« zu überschreiben, welches auch in Paket ubuntu-xsplash-artwork 0:0.8.5-0ubuntu1 ist