Customsongs on Menu



I have convertxtodvd and ive been using it for awhile to make my dvd’s. The whole thing is pretty simple and everything has worked great so far, but i can’t seem to get the mp3’s that i set to play at the title menu to play. I’ve tried to use mp3 files and none of them have seemed to work. So i was just wondering what im doing wrong or what i should be doing, to get these songs to play at my dvd menus. Thanks for all the help.