Sometimes when I purchase a certain item, it instantly Disconnects me.
 

It is happening right now with the Tinkerer's Bag. I can't buy it.

Did you have exactly the right of change on you for the purchase? I found EQ sometimes doesn't like your plat purse hitting exactly zero coins via a vendor purchase.

This is happening to me now as well with the same item.

Happens to me sometimes when I eat/drink until I can't anymore, then replenish my food/water and start moving other stuff around, then when I come back after the crash there will be a single food or water in my inventory. So I'd assume this kind of thing happens when an item bugs out and gets hidden on your cursor.

Experiencing this atm with the Tinkerer's Bag.
Can't buy it.
When I hit the "purchase"-button, it instantly disconnects me.

Ok, my problem is solved.

This happened to my Iksar Monk. I conned threateningly to the NPC, but I was too high, so it wouldn't attack me.

"Sneak" > stand behind NPC > right click to open purchase table > the NPC turns to me
>>> I had to WAIT till it turned away again from me. Now I could sell and buy without any problems.

Might help others in a similar situation.

Cheers,