Deploying a debug version of a vb.net app

Question

I have developed an application in vb.net. I use a dll that I build as part of a different project in my solution. For some reason I don't get the full functionality of my application with the dll built as a "release" version, but it does work if the dll is built as a "debug" version (that's a whole different problem). I don't have a problem, for now, using the debug version. However, the problem I'm having is I am trying to deploy the application to another system and if I deploy the debug version of the dll I get a runtime error (see below). I have the .net Framework installed. I'm just wondering what has to be installed in order to allow me to use the debug version of the new system?

See the end of this message for details on invoking 
just-in-time (JIT) debugging instead of this dialog box.
************** Exception Text **************
System.NullReferenceException: Object reference not set to an instance of an object.
   at tocapp.Form1.Form1_Load(Object sender, EventArgs e) in C:\Documents and Settings\gregh\My Documents\Visual Studio 2005\Projects\TOCApp2\TOCApp2\Form1.vb:line 104
   at System.EventHandler.Invoke(Object sender, EventArgs e)
   at System.Windows.Forms.Form.OnLoad(EventArgs e)
   at System.Windows.Forms.Form.OnCreateControl()
   at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
   at System.Windows.Forms.Control.CreateControl()
   at System.Windows.Forms.Control.WmShowWindow(Message& m)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
   at System.Windows.Forms.ContainerControl.WndProc(Message& m)
   at System.Windows.Forms.Form.WmShowWindow(Message& m)
   at System.Windows.Forms.Form.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: 2.0.50727.3607 (GDR.050727-3600)
    CodeBase: file:///c:/WINDOWS/Microsoft.NET/Framework/v2.0.50727/mscorlib.dll
----------------------------------------
tocapp
    Assembly Version: 1.0.0.0
    Win32 Version: 1.0.0.0
    CodeBase: file:///C:/Program%20Files/Sparnet/tocapp.exe
----------------------------------------
Microsoft.VisualBasic
    Assembly Version: 8.0.0.0
    Win32 Version: 8.0.50727.3053 (netfxsp.050727-3000)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Microsoft.VisualBasic/8.0.0.0__b03f5f7f11d50a3a/Microsoft.VisualBasic.dll
----------------------------------------
System
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.3053 (netfxsp.050727-3000)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System/2.0.0.0__b77a5c561934e089/System.dll
----------------------------------------
System.Windows.Forms
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.3053 (netfxsp.050727-3000)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Windows.Forms/2.0.0.0__b77a5c561934e089/System.Windows.Forms.dll
----------------------------------------
System.Drawing
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.3053 (netfxsp.050727-3000)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Drawing/2.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll
----------------------------------------
System.Runtime.Remoting
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.3053 (netfxsp.050727-3000)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Runtime.Remoting/2.0.0.0__b77a5c561934e089/System.Runtime.Remoting.dll
----------------------------------------
SparnetMapControl
    Assembly Version: 0.0.0.0
    Win32 Version: 0.0.0.0
    CodeBase: file:///C:/Program%20Files/Sparnet/SparnetMapControl.DLL
----------------------------------------
System.Data
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.3053 (netfxsp.050727-3000)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_32/System.Data/2.0.0.0__b77a5c561934e089/System.Data.dll
----------------------------------------
System.Xml
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.3082 (QFE.050727-3000)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Xml/2.0.0.0__b77a5c561934e089/System.Xml.dll
----------------------------------------
Oracle.DataAccess
    Assembly Version: 10.2.0.100
    Win32 Version: 10.2.0.100
    CodeBase: file:///C:/WINDOWS/assembly/GAC/Oracle.DataAccess/10.2.0.100__89b483f429c47342/Oracle.DataAccess.dll
----------------------------------------
System.EnterpriseServices
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.3053 (netfxsp.050727-3000)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_32/System.EnterpriseServices/2.0.0.0__b03f5f7f11d50a3a/System.EnterpriseServices.dll
----------------------------------------
System.Configuration
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.3053 (netfxsp.050727-3000)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Configuration/2.0.0.0__b03f5f7f11d50a3a/System.Configuration.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.

Answer 1

It looks like your "underlying dll" might have a bug that is vanishing as soon as you do a debug build; There are many potential causes for this, ranging from thread synchronisation issues (that vanish when DebugWrite() calls get removed from Release builds) right the way through to memory corruptions from poorly initiated memory.