VS2010: Debug And After Compilation - Monitor The Clipboard And Save Its Contents To A XML

I have seen a different behavior before, but this time my application just doesn't work properly when debugging, while it does everything perfectly after compilation.

My project is beginning and does just one thing: monitor the clipboard and save its contents to a XML. It has just one form (frmMain), which, when loaded, puts itself in Windows clipboard listening, via WIN32 API. Then, whenever receives a message, the form has to check if it's from clipboard and, if so, saves the actual contents.

The code is below:

Public Class frmMain

Private Const WM_CLIPBOARDUPDATE As Integer = &H31D
Private XmlDocument As System.Xml.XmlDocument

[CODE]...

So, as I've said, after compiling, everything works perfectly. However, when debugging the "AddItems" function is never called. I set a stop point in the line Win32 API is called (in frmMain_Load) and the execution NEVER STOPS THERE! Debugging line by line, I found out that after executing some lines from frmMain_Load, VStudio just jumps to WndProc and never comes back to frmMain. I mean, the form is shown, and the rest of its initialization code is never executed. Because of that, my form is never added to clipboard listening (this command is at the end of frmMain_Load) and, consequently, all messages my window receives are not from clipboard, and, therefore, nothing is saved.

Is it normal to VStudio just bypass some code because a event triggered other method? This could lead to lots of complications and it's not consistent with after compiling behavior. A proof that what I said is actually happening is this: I passed the last 5 lines from frmMain_Load (where the Win32API is called) to the beginning, so my program would call the API before initializing the XML file. OK, now what I have: the API is called, but the XML commands are never executed. Consequently, "AddNewEntry" is called, but I have a null-reference error, because my XML was never initialized. Have you ever faced that bizarre behavior? What can I do so my debugging is correct and I don't have to compile my program for each test I want to do?