Help me out here a little if you please. The pcs are in the ethereal plane and are facing an incorporeal creature. Is there any change to its status? its incorporealness does not change at all in relation to the PC's attacks? (like a pc attacks it with a non magic sword? It takes half damge from non ghost touch magic weapons?)
School transmutation; Level cleric 7, sorcerer/wizard 7Casting Time 1 standard action
Components V, S
Duration 1 round/level (D)
You become ethereal, along with your equipment. For the duration of the spell, you are in the Ethereal Plane, which overlaps the Material Plane. When the spell expires, you return to material existence.
An ethereal creature is invisible, insubstantial, and capable of moving in any direction, even up or down, albeit at half normal speed. As an insubstantial creature, you can move through solid objects, including living creatures. An ethereal creature can see and hear on the Material Plane, but everything looks gray and ephemeral. Sight and hearing onto the Material Plane are limited to 60 feet.
Force effects and abjurations affect an ethereal creature normally. Their effects extend onto the Ethereal Plane from the Material Plane, but not vice versa. An ethereal creature can't attack material creatures, and spells you cast while ethereal affect only other ethereal things. Certain material creatures or objects have attacks or effects that work on the Ethereal Plane.
Treat other ethereal creatures and ethereal objects as if they were material.
If you end the spell and become material while inside a material object (such as a solid wall), you are shunted off to the nearest open space and take 1d6 points of damage per 5 feet that you so travel.
Note the bolded passage.
If the creature is incorporeal because it's an ethereal creature, then it is considered material now since the PCs are on the ethereal plane. If it's incorporeal for other reasons, it stays incorporeal.