Weird thing about permissions

I just bought a hair, and it had an annoying particle script inside it. I deleted both the script and texture inside the little invisiprim, detached it and re-attached, but somehow there's still the particle effect (even though tools -> reset scripts will say "no scripts in object" or something like that). So I just deleted the invisiprim altogether, and that seemed to do the trick, however now the hair just magically became no copy. When I purchased it it was copy/mod/no trans, except for the no modify no transfer script inside it. This odd permission change seem to happen very often when I edit objects, especially when it involves deleting/inserting textures and scripts into mod/copy objects.
Does anyone know why this happens and how to fix it?

If it was copy to start with, then hopefully you edited a copy of the original and still have the original. If so, then you can simply delete the messed up one and then make a copy of the original one again, and edit that.

As far as the particle thing is concerned, deleting the script has no effect. Particles are a prim property, much like the size, shape, how it's been cut and such. Deleting a script will not stop a particle effect that has been applied. What you need to do is drop a kill particle script to change the particle effect to nothing such as:

default
{
    state_entry()
    {
         llParticleSystem([]);
    }
}

will stop the particle effect.

If you do not have the original unedited copy, then you're out of luck unless you contact the owner and see if he or she is nice enough to give you a new copy.

Also, most of the time, copies of copyable objects are not copyable, so that's why that particular item is no copy (it's a copy of the original).

I always make a backup before editing so I'm safe on that part.
But the weird thing is, if I drop the hair, then pick it up again without editing anything, the picked up copy is still copy/mod/no trans. However the moment I delete the invisiprim that has the particle effects, and pick up the hair, it becomes no mod. So it has something to do with that single prim, or attempting to edit items in general that changes it into no copy.

Try this, if it doesn't work you can laugh at me

Drop a copy of the hair on the ground
Rez a new cube next to it
Link the two such that the cube is a child prim of the hair
Then, unlink

Hopefully after doing this, for some reason, the permissions are no longer lost upon unlink

Edit: corrected, the new prim would need to be a child prim, not the root