Had the same problem today:
Invalid decoder state.
at gbMKS.mAgm5Z.j6i9L(Byte[] )
at Rebex.Net.SshSession.JZ4YLZ(Byte[]& )
at Rebex.Net.SshSession.1rsOcLZ(1VEj6UZ , Object[] )
at Rebex.Net.SshChannel.1rsOcLZ(Boolean , 1VEj6UZ , Object[] )
at Rebex.Net.SshChannel.Receive(Byte[] buffer, Int32 offset, Int32 count)
at gbMKS.uuA26Z.1IsOQMZ(Byte[] , Int32 , Int32 )
at gbMKS.PEQpz.1oSQZR(Int32 )
at gbMKS.PEQpz.2aErfC(1dRwomZ& )
at gbMKS.PEQpz.2aErfC(UInt32 )
at gbMKS.PEQpz.1eDJCS(UInt32 )
at Rebex.Net.Sftp.2bVMHOZ(udycp , String , Stream , Int64 , Int64 , 27NpLhZ )
at Rebex.Net.Sftp.2bVMHOZ(FileMode , udycp , String , String , Int64 , Int64 , Int64 , 27NpLhZ )
at Rebex.Net.Sftp.GetFile(String remotePath, String localPath)
at COINImport.COINDownloader.DownloadFiles(NetworkCredential credentials, String hostname, Int32 port, IEnumerable`1 files, String destdir, String dateformat)
at COINImport.Program.Main(String[] args)
DateTime=2012-08-31T07:04:42.4888907Z
For now, this has only occured once. Should it happen again I will let you know.