media player works perfect on PC but not Mac ??

hello all.
i've just spent all day trying some different things, but have gotten absolutely nowhere. i'm having a huge issue with my media player where it works absolutely beautifully on the PC, but not on the Mac. i've tested on two PCs, my mac and had 2 friends check it out on their macs. i've used this media player a lot before as it was a template from my company - the only difference between the two is that my songs are full length big files being loaded in versus the 30 second clips that i would use with the company. Here's what's happening:

www.goodnfilthy.com/indexDEV.html (click on the "Rock Over London, Rock on Chicago" section, only the "chillin" and "shake it" sections are working right now. disregard the "rock my socks off" section.

on the PC: you can hit the forward and backward buttons quickly without pausing and it will do exactly that, show a loader, and then play the song. this all works within seconds and has no lag time. it's exactly how i want it to work

on the MAC: if you hit the forward or backward buttons, it acts like its waiting until the entire next song is completely loaded before it will play it or something. the reason i think this is because a)it takes a LONG time to start playing the next song, but also b)it won't even show the loader. when it finally kicks in, it's like it doesnt need to show the loader because the whole song is loaded (by the way, the loader is set to only check for the first 80 frames of the song).

i've tried taking the exact file that was used for my company site (that works fine on the MAC) and have it call my songs instead of its original 30 second ones and it behaves the same troubling way. so i was thinking maybe its a size issue of my songs - but why would it work BEAUTIFULLY on the PC? do sound cards work differently on macs vs. PC's or something? does anyone have any thoughts at all?? thanks so very much. my brain hurts.

joanne