Need confirmation about Dreamcast ROM

greetings..
well the site now have lotsa DC ROM!and im thinkin about tryin one...
i'm downloading the DOA2 ROM...and try it on the chankast and NullDC emulators!
the problem is....the ROM is not recognized as a game ROM..its like a music track..
and the emu is always said "pls insert game cd!"im not askin about whats wrong with the emu...cause i know its not the place..
but i need confirmation about the ROM....is it workin or not?
any of u guys try it and or have running it (with emu or console)?thx...appreciate it a lot if anybody could confirm :)edit: nobody try one yet??!! ???

power stone 2 works fine on my nulldc, it is a .CDI file. however, my gauntlet legends is not shown in the open game browsing window, it is a .bin and .cue combo.i might just need to mount it with daemon tools, idk.btw, chankast is not as good as nulldc imho.

thx for the reply....
so its must be the rom problem...i see...or compatibility problem...
anyone have tryin another rom?