thanks guys. XMPlay seems to do the trick. it's kind of funny, though; apparently it will only heed the mod's looping instruction if i turn repeat on (referring to the little button with the curvy arrows), and if i turn repeat on it loops any mod with or without a looping instruction. yet in the options you can select to loop only if there's a loop instruction or only if the loop instruction doesn't point all the way to the beginning. so doesn't seem to make a lot of sense.
and one of my favorite mods, elysium.mod, which loops, won't load under xmplay. i click on it and it simply closes the file selection dialog and does absolutely nothing. :/ i wondered if perhaps it just doesn't support mods with more than 4 channels, although that's strange since it supports .it, .xm, .s3m, .mp3, .ogg, .wma, etc.