> I just want CMP to scan that directory and tell me what images I'm missing. As

Well..remember the 2 possible scan modes:
rompath\setname\file 1 to file n - for unzipped sets
rompath\setname.zip for zipped sets

now take a look at the datfile you're scanning. Most of the art packs use only one set. The setname for the control panels is 'cpanel'. So your rompath subfolder has be named cpanel and that cpanel subfolder needs all png files in it. Your rompath has to point to the parent folder of cpanel. And again remember:
rompath\setname\file 1 to file n - for unzipped sets
rompath\setname.zip for zipped sets

;)

Roman Scherzer
ClrMamePro