We haven't had any problems with staining and we cook in the trailer. There was another thread for the same problem that I recall reading here. I don't think they ever came back after asking their question. Someone did ask if anyone had talked to Winnebago but again no response. Is the staining located in just one area, only on doors, only on panels, etc? I'm wondering if it might be glue or maybe hidden knots reaching the surface over time.