Talent and Item inspection
 

When i inspect another player's talent's it just scrolls through diff trees even ones the player shouldnt have such as arm warlock talent tree lol.Also dosen't want to show equiped items tooltips

Shouldn't be caused by nUI. Between patches, Server restarts etc, it's very possible that your cache may be empty. That may cause on initial inspection a blank tooltip. If you close the inspect window and then re inspect the same toon do the tooltips show correctly? Had it happen a few times myself before I had even heard of nUI :)

The talent issue may also be the same thing. Cache files getting updated, or server lag interfering.

This seems to be a bug in the 3.1 patch that hasn't been dealt with yet, seen this myself with and without nUI.
Edit: That is the talent tree issue, I have not clue about the other.

One thing is to make absolutely certain that you do not have any other mods installed that do talent browsing. None... zero... zip... zilch. Because of the way Blizzard has implemented the talent inspection system, it is *impossible* for two mods to co-exist that are both inspecting other player's talents.

The symptoms you're describing are indicative of having another mod installed that is trying to do just that.

EDIT: If it matters any, I am begging and pleading with Bliz to fix the talent browsing system so mods that need that info can co-exist.