Ok I suspect it in
src/download/DownloadFile.java

/**
* The HOST_BUSY status is handled like an error status currently
*/
public static final int HOST_BUSY = 6;

But I better be honest - I got a lot of other stuff prioritized ...
And it is Code written by others - I don't know how long it would take me to see through it ...

But lets Please sombody who allready 'Gets it' make a fix