Teflon-coated pans: are they ever dishwasher-safe? I've had my T-Fal teflon fry pan for a year and a half, and have used it every morning. I treated it well, but since they said it was dishwasher-safe I did put it in the dishwasher from time to time. Now it's worn out.

Some non-stick teflon pans say they are dishwasher-safe, others don't. Is this a difference in the coating, or just a difference in the marketing? Should I always keep my teflon-coated pans out of the dishwasher?
Never bothered sticking them in a dishwasher as they are easy to clean in the sink.
2 rules I abide by in regards to them.
Never use metal utensils with them. Silicone or wood only.
Never overheat them. Stovetop only. Medium heat at most.