Doesn't work. There are two different pairs of boots I and a friend of mine wore that give the immunity to Entangle. The thing is, they dont really give immunity to it. Even while wearing the boots we were subject to entangle from spells, traps and webs. Was this intended, or just some kind of bug?
I think it's for the specific spell. Not other effects.
Indeed this is an old bug that is hardcoded into neverwinter nights unfortunately. You can never truly be immune to any area of effect spell that has a duration (as opposed to instant like a fireball) such as entangle, cloud of bewilderment, acid fog, cloudkill etc. It is not possible to fix. The immunity: entangle was never supposed to effect anything but the spell entangle as mentioned above.