Would like to report the same with Supercard DSONE. After beating your rival in the PWT, the two step off the stage and the announcer says to check the screen to see the next competition. In DeSMuME the game proceeds by zooming in on the screen and displaying the battle list. On the Supercard it just freezes. The spectators stop moving and their cheering stops, with the music still playing. Not even soft reset works. It's a crash.
Glad it's not just me - wouldn't mind this crash terribly if beating the Driftveil Tournament wasn't an actual plot point! Are you on White 2? Has anyone experienced this with Black 2?
EDIT: Didn't have to go back too far to find a recommendation to use a clean ROM in clean mode. Lord almighty it is sloooow!