I figured out RomCenter had an issue with using the dat files here to scan game images that are over 4GB.
Turns out that the utility that imports redump's dat's into RomCenter format didn't support size references
over 32bit (aka4GB). Anyways, the fix is available here from the link "DatUtil v2.46":
Just replace the datutil.exe in RomCenter with the one in the zip!