If your character has a high amount of strength, you can carry more than 25 items. Unfortunately, the Trade screen doesn't really accomodate that scenario.
If you're trying to get to, say, item #28 - you'll have to rely on the text field to know what you've selected, as the player's item list visually doesn't scroll past item #25.
I generated a mutant with, among other things, one extra (right) arm. Later in the game, I quaffed a mysterious liquid that gave me another extra arm. Here's the problem: the second extra arm appeared at the bottom of the Traits column on the character sheet, but can't be found in the inventory/equipment screen.
How am I supposed to roleplay a walking crime against nature with only three arms?
