Good catch, Scott (how are ya?).
I was going to suggest instead of using Drag and Drop from the Browser to set the Now Time to the desired insertion point (in this case the start of the project), select the target track (where you want the audio file to land) and then in the Browser Right Click over the desired file and select "Insert At Now".
This is how I insert files these days and it's way better/more accurate/reliable for me than Drag/Drop.
HOWEVER I'm not sure what happens to a Broadcast Wave in this situation (and I don't have any handy to test with AFAIK). I'm wondering if the "Insert At Now" option overides the Broadcast Wave position or not.
I'll try to do a test by creating a BW if need be but maybe Don (or someone else) could test this out just to satiate my curiousity and add to the forum archive searches.
Cheers!