This bug is really old, but it became more annoying since you get items in your cursor when your inventory is full.
If you have a menu(rightclick smth with several options) open and get an item into your cursor(if youre picking branches for examples) the menu gets stuck, and you can never rightclick again. Logging out is the only solution.
There is also a minor bug with the chat arrow. When youre in a party and the chat is invisible and someone writes smth and the party is dissolved you will get stuck with an orange arrow until another color triggers the effect (like pm or area chat while your chat is invisible).