Interface Builder Bug?

I ran across something I believe is a bug in the interface builder. I was 
creating a tab-layout and I created some sub-entities(tabs) for it. 

ex. tab-1, tab-2, tab-3  

On the "items" properties I set the list to:

'(("Home" tab-1) ("Add" tab-2) ("Edit" tab-3))

Then I saved the dialog and the "items" property in the code view has now 
changed to:

'(("Item name" tab-1) ("Item name" tab-2) ("Item name" tab-3))


I thought I had done something wrong until I edited it in the code view to say 

'(("Home" tab-1) ("Add" tab-2) ("Edit" tab-3))

and saved it again, then closed the dialog in the interface builder and 
reopened it. Kind of an annoyance, unless I'm missing something.

William