Please don't' make this descend into a debate about the terrible health issues regarding the stuff I know all about it but on this occasion risked it.
The microwave is only 3 months old. After about 2 mintues it started smoking and a terrible acrid smell filled the kitchen. I turned it off and opened it and found it had started melting inside.
I have just phoned the manufacturer who told me that I'd invalidated the warranty by using microwave popcorn in the microwave. I've asked them to send me a copy of warranty with that clause highlighted. They refused saying it wqsn't that simple 
AIBU to have put microwave popcorn in the microwave and not to have checked the warranty before doing so?