Since I'm using those hints from time to time, I've decided to put them here, so I don't need to google everytime I need them.

Gnome 3 autocomplete crash fix

Well to me honest, this isn't a fix but just a workaround, but hey! Wokrs for me ;)

sudo chattr +i ~/.local/share/recently-used.xbel

Filezilla drag&drop crash

sudo apt-get install curl
curl http://apt.wxwidgets.org/key.asc | sudo apt-key add -

Now let's add to /etc/apt/sources.list file:

deb http://apt.wxwidgets.org/ natty-wx main
deb-src http://apt.wxwidgets.org/ natty-wx main

and then:

sudo apt-get update
sudo apt-get install python-wxgtk2.8 python-wxtools wx2.8-i18n

Ubuntu shutdown without admin password

To do this, we just need to change the policy for shutting down. Edit the /usr/share/polkit-1/actions/org.freedesktop.consolekit.policy file and replace:

<action id="org.freedesktop.consolekit.system.stop-multiple-users">
  <description>Stop the system when multiple users are logged in</description>
  <message>System policy prevents stopping the system when other users are logged in</message>
  <defaults>
    <allow_inactive>no</allow_inactive>
    <allow_active>auth_admin_keep</allow_active>
  </defaults>
</action>

to:

<action id="org.freedesktop.consolekit.system.stop-multiple-users">
  <description>Stop the system when multiple users are logged in</description>
  <message>System policy prevents stopping the system when other users are logged in</message>
  <defaults>
    <allow_inactive>no</allow_inactive>
    <allow_active>yes</allow_active>
  </defaults>
</action>

Same for rebooting:

<action id="org.freedesktop.consolekit.system.restart-multiple-users">
  <description>Restart the system when multiple users are logged in</description>
  <message>System policy prevents restarting the system when other users are logged in</message>
  <defaults>
    <allow_inactive>no</allow_inactive>
    <allow_active>auth_admin_keep</allow_active>
  </defaults>
</action>

to:

<action id="org.freedesktop.consolekit.system.restart-multiple-users">
  <description>Restart the system when multiple users are logged in</description>
  <message>System policy prevents restarting the system when other users are logged in</message>
  <defaults>
    <allow_inactive>no</allow_inactive>
    <allow_active>yes</allow_active>
  </defaults>
</action>