There are a few problems with the handling of sortorder in the models. Those points are all related to each other:

1. New sortorders are created based on the number of rows in a table
2. When an entry is deleted, the sortorder is left untouched perhaps causing holes
   • E.g. sortorders 1, 2, 3, 4 and 3 is deleted leads to 1, 2, 4
3. Reordering is substracting/adding 1 to the sortorder, which is the problem when holes already exist.