That is REALLY strange. Let me update the copy O__O
Which route did you encounter this problem in? What scene?
Right at the beginning, after she first changes into the dress. And I played through to the first dance and it never appeared on her model. I think Valle's route? I can send a screenshot if you'd like.
Edit: I reopened the 32bit version and she's clothed now? Not sure what happened, but if I see it again I'll grab a screenshot. Super great game so far though!!!