Giver app doesn't work on Ubuntu 11.04

[Manolis Kapernaros]

I just installed Giver from Software Center and it doesnt work.
This is the output from terminal:

kapcom01@kapone:~$ giver
[Debug]: PhotoService static constructor called
[Debug]: New GiverService was created
[Debug]: We have the port : 41906
[Debug]: About to create the Avahi client
[Debug]: Adding Avahi Service _giver._tcp
[Debug]: GiverService:OnEntryGroupStateChanged was called state: Registering
[Debug]: Avahi Service _giver._tcp is added
Exception in Gtk# callback delegate
  Note: Applications can use GLib.ExceptionManager.UnhandledException to handle the exception.
System.DllNotFoundException: libX11.so
  at (wrapper managed-to-native) Egg.TrayIcon:XInternAtom (intptr,string,bool)
  at Egg.TrayIcon.OnRealized () [0x00000] in <filename unknown>:0
  at Gtk.Widget.realized_cb (IntPtr widget) [0x00000] in <filename unknown>:0
   at GLib.ExceptionManager.RaiseUnhandledException(System.Exception e, Boolean is_terminal)
   at Gtk.Widget.realized_cb(IntPtr widget)
   at Gtk.Widget.gtk_widget_show_all(IntPtr )
   at Gtk.Widget.ShowAll()
   at Giver.Application.SetupTrayIcon()
   at Giver.Application.InitializeIdle()
   at GLib.Idle+IdleProxy.Handler()
   at Gtk.Application.gtk_main()
   at Gtk.Application.Run()
   at Gnome.Program.Run()
   at Giver.Application.StartMainLoop()
   at Giver.Application.Main(System.String[] args)

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: giver 0.1.8-6
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic i686
Architecture: i386
Date: Thu Jun 23 21:04:11 2011
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release i386 (20110427.1)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=el_GR:en
 LANG=el_GR.UTF-8
 SHELL=/bin/bash
SourcePackage: giver
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.