python2.6 crashed with SystemError in commit()

[tr00per]

Binary package hint: python2.6

$ lsb_release -rd
Description: Ubuntu 9.04
Release: 9.04

$ apt-cache policy python2.6
python2.6:
  Zainstalowana: 2.6.2~rc1-0ubuntu2
  Kandydująca: 2.6.2~rc1-0ubuntu2
  Tabela wersji:
 *** 2.6.2~rc1-0ubuntu2 0
        500 http://pl.archive.ubuntu.com jaunty/main Packages
        100 /var/lib/dpkg/status

Some application suggested to download new stuff and tried to do it. The problem is in the same time Synaptic was up and running, downloading new packeges. I think the cause may be the lock on packages operations from Synaptic, that "feature installer" wasn't aware of.

ProblemType: Crash
Architecture: amd64
Dependencies:
 libgcc1 1:4.3.3-5ubuntu4
 zlib1g 1:1.2.3.3.dfsg-12ubuntu2
 gcc-4.3-base 4.3.3-5ubuntu4
 findutils 4.4.0-2ubuntu4
 libc6 2.9-4ubuntu6
DistroRelease: Ubuntu 9.04
ExecutablePath: /usr/bin/python2.6
InterpreterPath: /usr/bin/python2.6
NonfreeKernelModules: nvidia
Package: python2.6-minimal 2.6.2~rc1-0ubuntu2
ProcAttrCurrent: unconfined
ProcCmdline: python /usr/bin/install-package --install soprano-backend-sesame
ProcEnviron:
 PATH=(custom, no user)
 LANG=pl_PL.UTF-8
 LANGUAGE=
 SHELL=/bin/bash
PythonArgs: []
SourcePackage: python2.6
Title: python2.6 crashed with SystemError in commit()
Traceback:
 Traceback (most recent call last):
   File "/usr/bin/install-package", line 202, in commit
     apt_pkg.PkgSystemLock()
 SystemError: E:Nie udało się uzyskać blokady /var/lib/dpkg/lock - open (11 Resource temporarily unavailable), E:Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?
Uname: Linux 2.6.28-11-generic x86_64
UserGroups: