Saving data object when sort order is 0 pushes it to the end.

[MattyBalaam]

With the default example for onBeforeWrite, testing for !$this->Sort will return true if the current sort number is 0.

So, if you are saving in the detail form, it will then move this item to the last.

My solution for this was to change to checking for an integer:

!is_int($this->Sort)

[tractorcow]

Regression in 1.4

More information on this at #159

The above workaround will not work if saving and reloading a "new" record from the database, since the DB might assign 0 as default value.