Hi there!, I have this very strange problem:
I want to iterate through Outlook contacts located in a public folder, but iteration stops randomly giving different error codes, among them these ones: -833601531, -695189499, -625983483, -37732347. Everytime I get the same text message: "The operation failed". 
for (int i = 1; i <= mexicoContacts.Items.Count; i++)
{ 
if (mexicoContacts.Items[i] is Outlook.ContactItem)
{ 
Outlook.ContactItem contact = (Outlook.ContactItem)mexicoContacts.Items[i];
if (contact.LastName != null)
listBox1.Items.Add(contact.LastName);
}


}

Any Ideas?
Thanks...

Try checking the InnerException of your exception and see if this will give a more descriptive error message that what you are currently getting.

Hi Ron!
Some good news:
I added a try / catch block and now I always logoff from Outlook namespace... error shows me this:

Microsoft Office Outlook
A first chance exception of type 'System.Runtime.InteropServices.COMException' occurred in Phone Usage Reporter.exe at Outlook.ItemsClass.get_Item(Object Index)
at Phone_Usage_Reporter.formMain.linkUpdate_LinkClicked(Object sender, LinkLabelLinkClickedEventArgs e) in C:\Documents and Settings\itsadmin\My Documents\Visual Studio 2005\Projects\Toolbox\Phone Usage Reporter\Phone Usage Reporter\Form1.cs:line 39
and now it always reads 164 items... no more...

In C#, indexes are 0-based.  Given this, try changing the ones in red:
for (int i = 0; i < mexicoContacts.Items.Count; i++)
{ 

if (mexicoContacts.Items[i] is Outlook.ContactItem)
{ 
Outlook.ContactItem contact = (Outlook.ContactItem)mexicoContacts.Items[i];
if (contact.LastName != null)
listBox1.Items.Add(contact.LastName);
}

}

I tried, but seems Outlook has a 1-based array system... item 0 does not exist... I have something else: I can read item 166 but can't read item 165... strange... that makes me think it's something related to the way the item was saved...

Looks like there's something wrong with that item.  I suggest that you skip those items that gives you an error and just continue with the items after that and just report which ones are causing the problem.

hehe, sounds easy, but I don't know how to skip this... it seems like Outlook does not have an order in this numbers... :-)
maybe doing a foreach, but how would you do it?
thanks

One way to do it is to put your try/catch inside the for loop instead of outside:
for (int i = 1; i <= mexicoContacts.Items.Count; i++) { 


try {
if (mexicoContacts.Items[i] is Outlook.ContactItem) { 
Outlook.ContactItem contact = (Outlook.ContactItem)mexicoContacts.Items[i];
if (contact.LastName != null)
listBox1.Items.Add(contact.LastName);
}
}
catch (Exception exception) {
}

}

You're the man!!! I got all of them! got a big bunch of this:
A first chance exception of type 'System.Runtime.InteropServices.COMException' occurred in Phone Usage Reporter.exe
but there they are... I also changed for loop to this:

int total = mexicoContacts.Items.Count;
for (int i = 1; i <= total; i++)
because asking many times for mexicoContacts.Items.Count's value also raised an exception... do you any idea why this happened?
anyway it works now... thanks!!!!