Took me a while to figure out what was going on, but with PB 1.0.7 and WP 3.5.1, if I search for a term that appears in both pages and posts, the results overlap. See:
http://wp.bridgewater.edu/dparsley//?s=pinboard (5 posts over top of 1 page)
http://wp.bridgewater.edu/dparsley//?s=wordpress (5 posts over 3 pages)
Searching for a post-only term looks fine:
http://wp.bridgewater.edu/dparsley//?s=sous
I tried it with Twenty-Eleven and Twenty-Twelve, but the search results for those are just a boring old linear list.
Thank you for letting us know, we will fix this in the next release. If you want to manually correct it, open functions.php and replace this line:
itemSelector : '.post',
with this:
itemSelector : '.hentry',
Indeed that fixes it, thanks!