Unable to connect new Sony NWZ-A818 mp3 player to computer

[TheFaze]

I know that this might be a tired topic, but I just recently purchased two 8gb mp3 players, both being the Sony NWZ-A818 player; silver for myself and black for my wife.

However, both have been unable to connect to my computer, nor do they charge via USB. The players turn on, but then turn back off after nonuse. I ended up charging the players by connecting the players to my PS3.

My computer, home-built:
Windows XP Pro, SP2
Asus A8N-SL1 motherboard, Athlon 64x2 3800 dual core
Multiple USB 2.0 ports
1GB memory

Sony NWZ-A818, 8GB, "Plays for Sure" (haha)
No driver needed, just Win Media Player 11, which I have.

What I've tried with no positive results:
- resetting the player
- formatting the player to erase the files
- different USB ports on the computer, front and back
- rolled back WMP to 10
- when WMP10 didn't work, I upgraded back to 11, which still didn't work
- I installed the latest chipset drivers (although I haven't upgraded the BIOS just yet)
- tried to upgrade the USB drivers, but Windows Update couldn't do so

In every case, the "new hardware detected" window pops up, and windows wants to install drivers/software for the unit, but obviously, there's nothing that I can install.

If there's anything I can do, please let me know. I would greatly appreciate any and all help. If there's anything else you need to know, please ask. Thanks in advance for any help.