"Believe"

During a conversation with a friend this evening, I discovered we were using the word "believe" at cross-purposes. When I said "believe", I meant having any internal perception of an external fact, whether or not accurate (e.g. I believe that my desk is in my room since I can currently see it). But she meant having a hypothesis about something which has not yet adequately been confirmed (e.g. I see the desk and now I know it's there, I no longer believe it's there). I wonder how common this difference is, and how much disagreement it causes.