Hi folks,
My coworkers and I have been noticing this issue for a number of years now and I have finally decided to pursue an answer further than a single, fruitless google search.

We have an obsolete state in our PDM vault that is used when a file is superseded. Through various directives over the years, our department has found ourselves obsoleting part files and creating assemblies with the same file name (part number) in order to purchase raw material and add bevels or holes in house. When we do that, we create the new assembly from scratch and, although we don't have a standard work process for this, we often open the original drawing and Replace Model, then repair the drawing.

Frequently, when we replace a model in a drawing view (selecting ALL drawing views), we end up with the original obsolete part file in the SolidWorks PDM pane under the drawing file with the new assembly file immediately below it. Occasionally, the original file goes away, like we would expect it to, but it seems to stick around more often than not.
What in the drawing file is still referencing the obsolete file? All the drawing views now reference the new file.
Do you have any idea how to get rid of them?

P.S. I have edited all the properties on the old file from which the drawing might be pulling values and it appears that none of them still have any impact on the drawing at all.