In searching for 09-05-2011 acquisition date, I get items due on 09-05-2011. It looks like somehow the date due is getting dumped into the acqdate search index. What these search results appear to be saying is that my system doesn't have any items that are shown as acquired on 2011-09-05. The results should be empty, but the checked out items are showing instead.
I would like to test this bug but it's not clear from the description where the problematic search is being done.
I'm closing this with Nicole's permission because we no longer have enough information to test whether it is still valid.