Compact Framework 2.0 - WinCE 5.00 - Application crash - Newbye (:

Hi everyone,
I'm rewriting with SharpDevelop 2.2 a small application for Microsoft
Windows CE version 5.00 using compact framework 2.0.

When i compile, everything seems to work well on the PC, but when i
try to
exec it on Windows CE 5.00 my application starts good, then it crash
when i
push on certain buttons of menu..

The first part works well, it does a query to a db with the login
information and then it login to the real app.. then, on the next
menu,
starts with crashes when i call the other forms..

the first of them is :

*************************************************
InvalidCastException
at
MyNameSpace.MyForm1.InitializeComponent()
at
MyNameSpace.MyForm1.......ctor()
at
MyNameSpace.Menu.OpenMyForm1()
at
MyNameSpace.Menu.ButtonXYZclick()
at
System.Windows.Forms.Control.OnClick()
at
System.Windows.Forms.Button.OnClick()
at
System.Windows.Forms.ButtonBase.WnProc()
at
System.Windows.Forms.Control._InternalWnProc()
at
Microsoft.AGL.Forms.EVL.EnterMainLoop()
at
System.Windows.Forms.Applicatino.Run()
at MyNameSpace.MainForm.Main()
*************************************************

Another thing i noticed is that if I insert a pictureBox inside the
first
form of the application, it crashes in a similar way when i try to
exec it..
but is really strange 'cos i red that the pictureBox is compatible
with CF
2.0..
so... where's the mistery?
If you need addictional informations, please feel free to ask me and
I'll
reply ASAP!

I thank all of you who's gonna help me (:
am kinda newbye..

Luca