On the few custom tables that I've created they defaulted to displaying ID in numerical order. I added a .mod file to my system with the syntax to force it to order by the sym attribute. You could use a similar approach, but I'm wondering why it's different for you.
Add this to a .mod file and place in nx_root/site/mods. You'll need to update the object and factory to match your environment.
OBJECT object{
FACTORY factory{
STANDARD_LISTS {
SORT_BY "id";
WHERE "delete_flag = 0" ;
};
};
};
Edited, didn't save correctly.