MacBook Pro - OS X vs Windows timestamp on files

hello all,

So I'm a relatively new mac user and am having a nightmare of a time figuring this out. Basically it's simple, I download to a PC server all the music taht I get. I then in turn copy it to my mac using a usb key. I usually do a copy paste from the usb key to the mac drive. I use my music to dj so timestamps are very important because I want the newest (date created) ones to show up on the top of every folder.

Unfortunetly this isn't the case. Mac OS X is getting different timestamps than that of PC. They're not even consistant....ex: I have 10 files taht were all copied at the same time, some are showing one date, other another meaning all my new files copied, are all over the place within a folder with hundreds of files.

I'm using OS X 10.5.6 (Macbook Pro)

Please help!!