Obi is busy, so I'll try to answer..................This isn't a limitation in 365 - if you embed with a Paypal gadget you get this:
"Our widgets don't work on IE8. So sorry about that! Please upgrade to the latest version of IE or use a different browser."
Which is pretty funny considering many more people use IE8 than newer IE's, It works fine in Firefox etc. I'd ask the publisher how you can work around the problem - or look for a different widget. .