Questions about PubIt!

I've recently posted a few books on PubIt and no one at B&N has had the time to reply to my emails. Maybe someone here has the answers.

When I posted these ebooks I was asked if they had ISBNs. They didn't, but when they appeared on the site they did! So I wonder who is listed as the publisher, B&N or me, and if the ISBN can be used on other sites?

These books have a note on their B&N pages that states that they are not compatible with MAC or Blackberry. I don't know why

Thanks for the help.