Yep, add me to the list as well. Happens with 2.0 (will be trying 2.2 later) and Paypal Standard. My solution to the two emailed invoices was to put a condition in the "E-mail customer checkout notification" predicate. I used the "Check order status" condition and selected "In checkout" from the status list. If I used "Payment received", no emails arrived.
Sadly, no idea on the duplicated number of downloads (shows 2 instead of 1). Not a big deal at the moment, as I simply set the "restrict IP address" option to 1.