Expression Encoder 3: Green artifacts after encoding

Question

Some of the videos I encode using the Expression Encoder 3.0 have green lines at the bottom. Since I have no prior experience with encoding, I have no clue about why this is happening. Though I think it might have something to do with the format of the videos I am encoding. I am using some very basic code:

DirectoryInfo dInfo = new DirectoryInfo(@"E:\temp\wmv");

Job job = new Job();
job.JobId = "TESTING";
foreach (FileInfo fInfo in dInfo.GetFiles())
{
    Console.WriteLine("Adding file ---> {0}",fInfo.FullName);
    MediaItem mediaItem = new MediaItem(fInfo.FullName);
    mediaItem.OutputFileName = fInfo.Name;                    
    mediaItem.ApplyPreset(Presets.VC1BroadbandVBR);

    mediaItem.OutputFormat.AudioProfile = new WmaAudioProfile();

    job.MediaItems.Add(mediaItem);
}                


job.OutputDirectory = @"E:\temp\wmv";
job.CreateSubfolder = true;

job.EncodeProgress += new EventHandler<EncodeProgressEventArgs>(job_EncodeProgress);
job.Encode();