Change the command in the option_track_show from a 'show global overlay' overlay command to a 'show overlay' command with the same parameters to open 'music_track_options'. This should fix your problem (tried it here on my computers and that seemed to do it).
Another option is to remove the options_track_show event from the musicview category Events (tab)/'Click Event', then select the *EDIT* MUSIC CATEGORY on the music screen. *EDIT* Select the Category/General tab, and next to 'Info screen' it will most likely say 'musicdetails'. Change this to 'overlay:music_options_tracks' . This will also cure your problem (again tried it on my computers).
Now why did the show global overlay command not work...not to sure as according to Colby's Event Variable document the 'show global overlay' command should show the overlays on both server and client pcs.
It was also explained to me in more details
here.
Hope this was helpful.
P.S. The KISS skin is awesome...a great skin to learn from.
*EDIT*
I saw you post in the skin forum to Buddabing. I don't think this overlay thing is a bug with just his skin. I think it is a bug with the show global overlay command. But Steven is so wrapped up with Xlobby3 and not taking care of plugging up XLobby2, I'm not even sure if it is worth reporting anymore.