Off-hand items

I have just gotten a Disciple off hand item that adds +healing to my spells and 5 energy. I equiped it and it worked fine becuase I had the (req. +4 is disciple) but now that i have upped the the points to 6 the item now has the no smoking circle with a slash through it symbol.

Is this case for all items. If it say you are req. to have a certian amount of points in an attribute line for it work then you can not use that item if you go over that amount?

Seems odd to me.

Off-hand artifacts do not work with a two-handed item, like a staff. You have to use a wand, sword, axe, cane, etc. Thus the "disabled" symbol.