AutoCAD 2010 :: Stubborn Blocks Refuse To Be Purged?

I want to attach an xref of "12015.01 - 69 East Ave   BB02", but AutoCAD gives me the following error:

Error: "12015.01 - 69 East Ave BB02" is already a standard block in the current drawing. *Invalid* 

First I checked to make sure there were no referenced blocks or xrefs in the drawing. I then attempted to purge the following blocks:

"12015.01 - 69 East Ave   BB00" 

"12015.01 - 69 East Ave   BB01"

"12015.01 - 69 East Ave   BB02"

Nothing happens. I click on "View items you cannot purge" and highlight any of those blocks and this is what I get:

This block definition cannot be purged if:

-- It is nested inside another block.
-- It is inserted in the drawing.
-- It is an attached xref drawing.

If I copy and paste the drawing into a new file, the blocks does not copy over, so it is obviously a problem with the file and not the drawing (if that makes any sense). I would simply replace the file, but all of my CD's Xref those three files and I don't have the time to go through and re-insert all of them.