I recently downloaded the Android Version of Winamp from the Android Market for my Samsung i5801 a.k.a Galaxy 3.
It was running perfectly until i connected the phone to my computer via the USB.
When i plugged the USB cable, a warning message came that Nulllsoft Winamp needs to close (Even though the app was not open), and i clicked close. And then my phone showed a message that your phone SD Card storage is not accessible and the same message showed on PC again when i accessed phone via the Samsung Kies software. I tried restarting the phone, unmounting the SD card a couple of times,but still the same problem when i tried to plugin the USB.
Later , i decided to uninstall the WInamp Android App and then tried to Plug in the USB cable and its working fine now, i can access my memory card.

WInamp guys, please fix this bug as soon as possible,