That's odd. It should certainly continue to show you the rep of a node, after you run out of votes. It does stop showing you the voting buttons though, maybe you are looking at nodes that you haven't voted on, and getting confused?
What do you then see? Could you link to a screenshot?
Screenshot is a good idea.. don't think I've gotten confused, though, as I noticed it a couple days in a row and then went through yesterday to the nodes I know I voted on..
Let me do a screenshot when (and if) I run out of votes today.
Also: I was using some on-site CSS, and have removed it temporarily, so will test with both CSS and no CSS, on the of-chance that had something to do with it