Setting gsharkdown's proxy preference to "Use system configured proxy" adds a forward slash at the end of the string.
If the system-wide proxy is set to 127.0.0.1:6666, this error message shows:
GrooveShark service has probably changed or is not working! gSharkDown will not works propperly, so please be patient until we find a solution. Also, this may usually caused by a proxy misconfiguration please check your proxy configuration.
The error was: invalid literal for int() with base 10: '6666/'
Manually setting proxy details (same host/port) brings everything back to normal again.
Using gSharkdown 0.6.7 on Ubuntu 10.10
Cheers and keep up the great work!