Samsung YP-U2R problem..

The main problem I'm having right now is that I can't recharge my (Samsung YP-U2R) mp3 player anymore via USB 2.0.

I'll start from the beginning, when I first got my mac mini (a bit more than a month ago)..

When I first connected my Samsung YP-U2R to my mac it went as expected; the USB-drive icon appeared on my desktop and it started charging. I also tried using it with iTunes which didn't work, but oh well, that's not the problem here..

On that day, when my Samsung mp3 player was fully charged after about 2 hours or so, I went to disconnect it by dragging the Icon on the Desktop into the Trash (which changes into an eject-button). What happened was the Icon disappeared for one or two seconds but then Re-Appeared ⚠. I tried ejecting two more times and the same thing happened. So I decided to risk it and just unplug my mp3 player from the USB2.0 port (actually from apple's USB extension cable) while it was actively 'charging' and.. simply connected; which supposedly is bad for mp3 players and such.

A couple of days later I needed to recharge my Samsung YP-U2R again. Though when I connected it, no Icon appeared...

To be exact: when I plug it in now...
a) no icon appears on the desktop indicating that I have connected it
b) my mp3 player's display says "Connected." and then "Charging..."
c) after ten seconds my mp3 player says "Disconnected." and stops charging!

mp3 player:
Samsung YP-U2R
I could only find a german page for my Samsung model, Samsung's US site doesn't have it indexed..
http://av.samsung.de/article.asp?artid=14ca2b40-4da6-4126-befe-1beb1070c6c8

I am planning to get an iPod nano as soon as I have enough money, but I hope someone can help me because I really like listening to music whenever I'm outside! The iPod is still a few weeks away 😟

Thank you very much in advance!