The stereo has all of the dances on it in my game - the only GLS hack that I can find in my Downloads is
this one from Lord Darcy but I don't think that affects the stereo at all. Do you perhaps have the hula and slap dance fixes from Dizzy? The dances only appear on the stereo if the Sim is in the same room with it.
I do have Dizzy's mod, and the sim is in the same room. All other stereo's are fine -- only the GLS one is borked. I'm pretty sure I have LD's mod in my game, but I'll re-download it to be sure. Thanks!
ETA: Ah, a case of tight pants -- it was Dizzy's hula and slap dance mods that broke the GLS stereo. Removing them fixed it. I'll have to drop him a note about it.