IGI NVidia data sources playback bug
If you have two data sources, one is an IGITracker and the other a NVIDIA video, on start up
niftkIGIDataSourceUtils::GetPlaybackIndex gets called. If the tracker source directory is started before the video, for example PolarisSpectra_0 then QmitkIGIVideo then all is good. However if it attempts to start the video source first, for example NVidia_SDI then PolarisSpectra_0, it fails because NVidia_SDI has no subdirectories. This is dependent on the naming of the directories.