Nautilus don't want to mount partitions in Gnome Classic when Gparted is running

[pioruns]

Binary package hint: nautilus

$ uname -a
Linux ubuntu-desktop 2.6.38-8-generic #42-Ubuntu SMP Mon Apr 11 03:31:24 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux

$ lsb_release -rd
Description: Ubuntu 11.04
Release: 11.04

$ apt-cache policy nautilus
nautilus:
  Zainstalowana: 1:2.32.2.1-0ubuntu13
  Kandydująca: 1:2.32.2.1-0ubuntu13
  Tabela wersji:
 *** 1:2.32.2.1-0ubuntu13 0
        500 http://gb.archive.ubuntu.com/ubuntu/ natty/main amd64 Packages
        100 /var/lib/dpkg/status

What you expected to happen:
I login to Ubuntu, Gnome Classic session (with Compiz effects). I clicked Places button (or open Nautilus window and choose from right menu). Then I choose any partition to mount (I have some NTFS and ext4 on my computer, on two harddrives). Partition should mount in the system and new Nautilus window with contents should open, so I can browse files. It happening in all Linux system that I have (for example Debian with Gnome - I click partition name and it mounting and window opens).

What happened instead:
nothing happened. I clicked all partition one by one, they won't open. I tried 'gksu nautilus', but Root's Nautilus window don't have list with partition which I can mount, so I cannot click anything.

WARNING: It happening ONLY, when Gparted is running. I just realize it now.