Dave investigates two very serious issues with jitter on the Rigol DS1000Z series oscilloscopes, including the DS1104Z and new DS1054Z Some sort of modulated sampling/trigger jitter problem at 5 microsecond intervals (the "5us jitter problem"). And severe jitter with the AC coupled trigger mode, a problem which is also present on the DS2000 series scopes as well.
NOTE: So many people have been confusing AC trigger coupling with AC input coupling people will be more familiar with. This issue has *nothing* to do with AC input coupling, it is AC trigger coupling!
Mads from EcProjects found the 5us jitter problem: https://www.youtube.com/watch?v=dHQ4MsMFJTk#t=172 https://www.youtube.com/user/EcProjects