Creo Parametric 3.0 won't save new versions of files
I am having a problem when saving files in Creo Parametric 3.0. It happened to me for the first time and I really don't know what to do. I can normally draw a new model, save it and it will be ok, but if I later modify the same model, save it again and close the program, the model goes back to initial state when I reopen the program (changes don't save). I'm not doing anything different than usual, have working directory set up properly and all that. Even if I save it as a backup, it goes back to initial state. Thank you for your help.

