OK, I have here version 3.101 and after doubling a33aaa02.chd = a33aba02.chd, a33jaa02.chd = a33jba02.chd & a34jaa02.chd = a34jba02.chd I still get every time:

Dance Dance Revolution 4th Mix Plus Solo (G*A34 VER. JAA) [system: System 573 BIOS - folder: ddr4mps - size: 525kb]
wrong name: D:\MULTI-FLIPER\mame\roms\chd\a34jaa02.chd [wrong: a34jaa02.chd] [right: a34jba02.chd] [not fixed]

Dance Dance Revolution 4th Mix Solo (G*A33 VER. ABA) [system: System 573 BIOS - folder: ddr4ms - size: 517kb]
wrong name: D:\MULTI-FLIPER\mame\roms\chd\a33aaa02.chd [wrong: a33aaa02.chd] [right: a33aba02.chd] [not fixed]

Dance Dance Revolution 4th Mix Solo (G*A33 VER. JBA) [system: System 573 BIOS - folder: ddr4msj - parent: ddr4ms - size: 517kb]
wrong name: D:\MULTI-FLIPER\mame\roms\chd\a33jaa02.chd [wrong: a33jaa02.chd] [right: a33jba02.chd] [not fixed]

Perhaps I should enable or disable some option? The only option I have checked is to allow CHDs on ROMPath root.

> The latest version of cmpro is 3.100c. Update.
> By the way, you have to double the chd anyway. Both sets use the same chd (with
> different names though) but they don't share a parent/clone relationship.
>
>
> Roman Scherzer