Paula, I have a plate in my warmer too as well as the rod rack. The first unit I got was just deemed 'defective'... no reason in particular. Just a manufacturing defect.
The crack is hard to see when the unit has cooled down, but is very visible once it heats up, in my case. Thanks for checking yours.
PS: I was a good girl and only got 1 lb of the Frog Green. I really hope it's the 'original' tone. The second time I ordered it, I got a green that looked like Devardi Lily Pad, not Frog Green. I don't know if the glass was mislabeled or it was a different batch that came out different than the 1st. Can't wait to get the box!