Controls disappearing, but can't replace

Hi,

     I have weird things happening on my webform.  I was in design mode, turned to listen to an office conversation, and when I turned around, a textbox and a combo box were gone.  One of them became a little grey button that said something about couldn't form control or something.  But I deleted it.  Then I tried to replace them.  If I click in the dropdown at the top of the properties box, there is no control listed with the names of the two that are gone.  But if I make a new textbox or combo and try to name them what the old ones were called, it tells me invalid property, a control already exists with that name.  In the HTML code I can't find an instance of those names either.  What happened to me?

JP