the File Name setting wont take the [Increment] Command, you can only use that in the first page in the If file exists section.
in the If file exists section, set it to rename the new file using the default [FileName]_[Increment] setting.
in the second step, only use the property ID form element binding, with out adding the [Increment]:
'FileName' => "".((isset($_POST["propertyID"]))?$_POST["propertyID"]:"") ."",
This wont be 100% what you are after, the first image will be named:
51.jpg
but further images will be named:
51_1.jpg
51_2.jpg
51_3.jpg