I think this was fixed and here it goes again?
Osu! did not crashed though, just a popup message that contains this things...

And something mentioned like "Index was out of range. Must be non-negative and less than size of the collection. Parameter name: index."

See the end of this message for details on invoking
just-in-time (JIT) debugging instead of this dialog box.

************** Exception Text **************
System.ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index
at System.ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument argument, ExceptionResource resource)
at System.ThrowHelper.ThrowArgumentOutOfRangeException()
at osu.Audio.AudioEngine.get_CustomSamples()
at osu.Audio.AudioEngine.LoadSampleSet(SampleSet s, Boolean force)
at osu.GameModes.Edit.Forms.TimingEntry.radioNormal_CheckedChanged(Object sender, EventArgs e)
at System.Windows.Forms.RadioButton.OnCheckedChanged(EventArgs e)
at System.Windows.Forms.RadioButton.set_Checked(Boolean value)
at osu.GameModes.Edit.Forms.TimingEntry.listBox1_SelectedIndexChanged(Object sender, EventArgs e)
at System.Windows.Forms.ListBox.OnSelectedIndexChanged(EventArgs e)
at System.Windows.Forms.ListBox.set_SelectedIndex(Int32 value)
at System.Windows.Forms.ListBox.set_SelectedItem(Object value)
at osu.GameModes.Edit.Forms.TimingEntry.UpdateAll()
at osu.GameModes.Edit.Forms.TimingEntry.numericOffset_ValueChanged(Object sender, EventArgs e)
at System.Windows.Forms.NumericUpDown.OnValueChanged(EventArgs e)
at System.Windows.Forms.NumericUpDown.set_Value(Decimal value)
at osu.GameModes.Edit.Forms.TimingEntry.listBox1_SelectedIndexChanged(Object sender, EventArgs e)
at System.Windows.Forms.ListBox.OnSelectedIndexChanged(EventArgs e)
at System.Windows.Forms.ListBox.set_SelectedIndex(Int32 value)
at System.Windows.Forms.ListBox.set_SelectedItem(Object value)
at osu.GameModes.Edit.Forms.TimingEntry.UpdateAll()
at osu.GameModes.Edit.Forms.TimingEntry.button2_Click(Object sender, EventArgs e)
at System.Windows.Forms.Control.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ButtonBase.WndProc(Message& m)
at System.Windows.Forms.Button.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)


************** Loaded Assemblies **************
mscorlib
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.42 (RTM.050727-4200)
CodeBase: file:///C:/WINDOWS/Microsoft.NET/Framework/v2.0.50727/mscorlib.dll
----------------------------------------
ezencryption_lib
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.42 (RTM.050727-4200)
CodeBase: file:///C:/WINDOWS/assembly/GAC_32/mscorlib/2.0.0.0__b77a5c561934e089/mscorlib.dll
----------------------------------------
System.Windows.Forms
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.42 (RTM.050727-4200)
CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Windows.Forms/2.0.0.0__b77a5c561934e089/System.Windows.Forms.dll
----------------------------------------
System
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.42 (RTM.050727-4200)
CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System/2.0.0.0__b77a5c561934e089/System.dll
----------------------------------------
System.Drawing
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.42 (RTM.050727-4200)
CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Drawing/2.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll
----------------------------------------
License
Assembly Version: 1.0.0.0
Win32 Version: 2.0.50727.42 (RTM.050727-4200)
CodeBase: file:///C:/WINDOWS/assembly/GAC_32/mscorlib/2.0.0.0__b77a5c561934e089/mscorlib.dll
----------------------------------------
ziplib
Assembly Version: 1.0.0.0
Win32 Version: 2.0.50727.42 (RTM.050727-4200)
CodeBase: file:///C:/WINDOWS/assembly/GAC_32/mscorlib/2.0.0.0__b77a5c561934e089/mscorlib.dll
----------------------------------------
osu!
Assembly Version: 1.0.0.0
Win32 Version: 2.0.50727.42 (RTM.050727-4200)
CodeBase: file:///C:/WINDOWS/assembly/GAC_32/mscorlib/2.0.0.0__b77a5c561934e089/mscorlib.dll
----------------------------------------
osu
Assembly Version: 1.0.0.0
Win32 Version: 1.0.0.0
CodeBase: file:///D:/Games/Osu!/osu.DLL
----------------------------------------
Microsoft.Xna.Framework
Assembly Version: 1.0.0.0
Win32 Version: 1.1.10405.0
CodeBase: file:///D:/Games/Osu!/Microsoft.Xna.Framework.DLL
----------------------------------------
System.Configuration
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.42 (RTM.050727-4200)
CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Configuration/2.0.0.0__b03f5f7f11d50a3a/System.Configuration.dll
----------------------------------------
System.Xml
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.42 (RTM.050727-4200)
CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Xml/2.0.0.0__b77a5c561934e089/System.Xml.dll
----------------------------------------
msvcm80
Assembly Version: 8.0.50727.163
Win32 Version: 8.00.50727.163
CodeBase: file:///C:/WINDOWS/WinSxS/x86_Microsoft.VC80.CRT_1fc8b3b9a1e18e3b_8.0.50727.163_x-ww_681e29fb/msvcm80.dll
----------------------------------------
Microsoft.Ink
Assembly Version: 1.7.2600.2180
Win32 Version: 1.7.2600.2181
CodeBase: file:///D:/Games/Osu!/Microsoft.Ink.DLL
----------------------------------------
osu!common
Assembly Version: 1.0.0.0
Win32 Version: 2.0.50727.42 (RTM.050727-4200)
CodeBase: file:///C:/WINDOWS/assembly/GAC_32/mscorlib/2.0.0.0__b77a5c561934e089/mscorlib.dll
----------------------------------------
System.Web
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.42 (RTM.050727-4200)
CodeBase: file:///C:/WINDOWS/assembly/GAC_32/System.Web/2.0.0.0__b03f5f7f11d50a3a/System.Web.dll
----------------------------------------
Accessibility
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.42 (RTM.050727-4200)
CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Accessibility/2.0.0.0__b03f5f7f11d50a3a/Accessibility.dll
----------------------------------------

************** JIT Debugging **************
To enable just-in-time (JIT) debugging, the .config file for this
application or computer (machine.config) must have the
jitDebugging value set in the system.windows.forms section.
The application must also be compiled with debugging
enabled.

For example:

<configuration>
<system.windows.forms jitDebugging="true" />
</configuration>

When JIT debugging is enabled, any unhandled exception
will be sent to the JIT debugger registered on the computer
rather than be handled by this dialog box.