FAUBELSTER  I'm attempting to use this app to join 38 files into a single dmg file. It concats the 1st file OK (albeit slow...). When I choose the 2nd file to concat, I get an overwrite warning. It just wants to overwrite rather than join the files.

I've also selected all 38 files and dragged onto the icon and selected concat: each successive file overwrites the next.

I've troubleshooted the obvious: There is nothing wrong with file names. aap.dmg.001, aap.dmg.002, etc

Appreciate any suggestions to make this work or a suitable alternative app.  
(Version 2.5)