Keepass2 crashes on opening second keystore file

[JThoennes]

Steps to reproduce

1. Open keepass2 with default file (database)
2. Open second database:
* File / Open ...
* select existing database
* Open
* Enter Master Key
3. New tab appears, new database is selected
4. Switch back to previous database (1st)
* Expected: tab with previous is selected and shown in the tab row
* Actual: previous db is selected but tab line is empty
5. Clicking in the tab line on the very right side leads to the crash:

System.Windows.Forms
  at System.Windows.Forms.TabControl+ControlCollection.Add (System.Windows.Forms.Control value) [0x00000] in <filename unknown>:0
  at System.Windows.Forms.Control.set_Parent (System.Windows.Forms.Control value) [0x00000] in <filename unknown>:0
  at System.Windows.Forms.Control..ctor (System.Windows.Forms.Control parent, System.String text) [0x00000] in <filename unknown>:0
  at (wrapper remoting-invoke-with-check) System.Windows.Forms.Control:.ctor (System.Windows.Forms.Control,string)
  at System.Windows.Forms.NativeWindow.WndProc (IntPtr hWnd, Msg msg, IntPtr wParam, IntPtr lParam) [0x00000] in <filename unknown>:0
  at System.Windows.Forms.XplatUIX11.DispatchMessage (System.Windows.Forms.MSG& msg) [0x00000] in <filename unknown>:0
  at System.Windows.Forms.XplatUI.DispatchMessage (System.Windows.Forms.MSG& msg) [0x00000] in <filename unknown>:0
  at System.Windows.Forms.Application.RunLoop (Boolean Modal, System.Windows.Forms.ApplicationContext context) [0x00000] in <filename unknown>:0
  at System.Windows.Forms.Application.Run (System.Windows.Forms.ApplicationContext context) [0x00000] in <filename unknown>:0
  at System.Windows.Forms.Application.Run (System.Windows.Forms.Form mainForm) [0x00000] in <filename unknown>:0
  at KeePass.Program.Main (System.String[] args) [0x00000] in <filename unknown>:0
Void Add(System.Windows.Forms.Control)

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: keepass2 2.25+dfsg-1ubuntu0.1
ProcVersionSignature: Ubuntu 3.13.0-46.79-generic 3.13.11-ckt15
Uname: Linux 3.13.0-46-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.14.1-0ubuntu3.7
Architecture: amd64
CurrentDesktop: Unity
Date: Mon Mar 16 10:38:06 2015
InstallationDate: Installed on 2015-02-20 (23 days ago)
InstallationMedia: Ubuntu 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140722.2)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=de_DE
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: keepass2
UpgradeStatus: No upgrade log present (probably fresh install)