You would think it would be easy, given that DVD Profiler flags duplicate titles when you add them, but there doesn't appear to be an easy way to see them from the database.

The only way I can think to suggest would be to view the owned list alphabetically by title. That would group duplicate titles together at least.

To break the task up into chunks, filter on Title, Starts With so you can do movies by the first letter of their title.

Thanks Mediadogg!  The Double Dip plug in worked great! 

Mreeder50: There is that approach also but I was looking for a tool to run over my entire collection and flag those duplicates I need to address.  Your way is fine for when checking on a few titles that you are considering purchasing new versions of to see what you already have and see what special features are in common.  I use variations on that over time.

As I'm getting somewhat forgetful I'm posting this for my benefit as much as for my hope that it might be beneficial to someone checking for duplicates.
Here's the procedure:
First, install the "Find double dips" plugin.  This plugin works great but, at least for me, has one serious omission; it doesn't display the disc locations.
Moving on,  Click the "Collection" tab in Profiler and then click Find Double Dips.
In the Double Dips window Click the "Start Searching..." tab.
When the search is complete select the "File" menu and click "Flag Listed Profiles" and then exit the plugin.
Now, right click on any column heading in the Profiler "Collection List" window and then "Sort by" and then "Flagged First".
If you don't have many dupes you're probably good to go at this point but I had quite a few and wanted a printout so I created a Report that provide enough info to verify the titles were, in fact, the same along with the locations.  As Reports created with the latest Profiler version are not being accepted, I've uploaded it to my Box account and here's the link
The Report will have to be copied to the My Documents/DVD Profiler/Reports folder so that Profiler can find it.  Pay attention to the Box set contents setting before running the Report.
Jim F.