USB connected device showing 0 free space?

[Jejeymccheese]

I recently installed winamp PRO on Windows 7. I successfully connected to my android device (Samsung Charge) via WiFi with no problems, transferred a few songs, no problem. However The WiFi signal here is extremely weak so to speed up the process of transferring music to my phone I decided to connect via USB. When I did that Winamp did not recognize my phone as the same device, instead it showed up as an external drive and asked me if I would like winamp to manage the device. Upon saying yes the "drive" showed up with 0.0 MiB available. When I attempt to transfer music it tells me I have run out of storage space. My phone has internal storage of 2 GB and an SD card with 32 GB. So the question is, what am I doing wrong? I've enabled auto mount on the android app, which seems to be working correctly. My computer recognizes the device/storage capacity just fine but winamp does not. Also, why would it not recognize it as the same device?

Help!