Navigation through a file on the outline pullout

When I use the up/down arrows to navigate through the slips in a DoxCycle file using the Organize/Outline pullout, I often have the arrows stop working at particular slips. Once that happens I have to click on the next slip to move on.

It is intermittent and I have been trying to isolate the issue, but so far it seems happens with documents that were incorrectly classified and that I have reassigned (usually not with the classification assistance but using the field at the top of the document).

Speaking of the fields at the top of the document, I find that when I tab across, the movement that should take me from the taxpayer to the category field instead jumps me to different document.