If I plus a USB 2.0 capable device into a USB 1.1 port, Windows warns me of what I've done and says that I will be restricted to USB 1.1 speed.
If you haven't seen this message, maybe your mp3 player isn't USB 2.0 capable. To use USB 2.0 Hi-Speed, both the device and port need to be capable, not just the port.
However, any combination of USB device/port
will work (but maybe not at the fastest possible), it's called universal for a reason
.