The best approach is not to leave anything in user.obp that you want to keep permanently - set up some folders for your objects (I organise mine into categories, e.g. architecture, plants, furniture, etc.) and export the objects into these as soon as you have created them. That way your objects are stored singly, and if one does get corrupt, it's only one, not the whole lot. When you want to use one of them just import it into user.obp, put it into your scene, and clear it out of user.obp before you shut down Bryce (after you've saved your scene!) The difference between the Poser libraries and user.obp is that the Poser objects are all separate files that Poser loads in as required, but user.obp is a single file containing all your user-created models. Every time Bryce starts up it loads them all in, and if you add, remove or update one it writes the whole file out again. If it corrupts the file in the process, which it seems to be good at doing, there's no way you can get into this file (unless you're a Bryce programmer)and unscramble it to rescue your objects. Some people don't seem to have this problem, some do, I've no idea why. I have had so much trouble with it that I avoid using .obp now as much as possible. If I can save objects in an alternative format, such as .3ds, I do, and store their textures or .mat files with them. This also uses less space than using .obps