The XMMS plugin provided in media-sound/audiocompress-1.5.1 allows you to enter 0 for some (all?) of the settings in the Audio Values tab of its configuration (right click on XMMS -> Preferences -> Effects tab -> (select KOMPRESSOR CRUSH XMMS in list) -> Configure -> Audio Values). For some (most? all?) of these settings, if you do set it to 0 and attempt playback, XMMS quits with a SIGFPE.
Can you make a patch to fix this or report it upstream? I don't have the time to fix it myself, and it's just some error-catching to guard against user errors in the configuration.
marking upstream as this isn't a gentoo issue...