hi, i've been away from my computer for a while (actually quite a good thing to do) But now I'm back with questions when modeling I usually convert from polys to subd's. This goes back and forth a couple of times to add extra geometry in poly mode and so on. Last time I converted back from subdiv's to polys added some geometry and then back to subdiv's. After I did that I noticed that some changes I made earlier had disappeared. Just subtleties, but still anoying. The geometry I added was in a completely different part of my model then were my details disappeared, so I think that cannot be the reason. Anyone any ideas why this happens? thanks