Running into the same problems with the Battlefield quests (in Act I) with a freshly-started 1.4 game. I complete the quest fine, but if I ever sell the item, or even move the item around in my inventory, the quest comes back in my quest list. This particular quest was for an item "Bull's Regular crossbow of the fox"
There's an item I picked up in Act 4 that does the same, made it a spoiler just in case:
<span class='standouttext'>Spoiler : </span><span class='spoiler'> The bone of the ancestor thingumy that you kill the two guards for during a 'test' (act 4 floor 3). </span>
I dragged that and dropped it in inventory (to re-arrange my items) and I got the entry about it in my quest log again.
