Hello
I just noticed this post so I thought that I would reply.
I live in Canada and sterilize and heat my bottles in the microwave. I bought a microwave sterilizer from avent here in Canada so it is legal. LOL
I noticed this warning when I brought dd home from the hospital and as a paranoid first time mom I actually called the formula company (Nestle) and asked them to explain this in further detail. They couldn't give me a clear concise answer as to why I shouldn't sterilize the bottles in the microwave. She just warned me against all microwave use for sterilizing and heating of bottle for infants and the microwave can cause uneven heating of the formula in the bottle. There must have been a lawsuit of some sort.
Anyways, I continued to sterilize using the microwave.