This has also really bugged me since the alpha. The biggest annoyance is that the order of your items in the inventory grid gets automatically (and apparently randomly) re-shuffled when you go to a trading screen, which makes selling items unnecessarily inconvenient. The best solution would be the addition of a "junk bag," where you could use a keystroke to stash new loot for later one-click resale. But since that would probably be a pretty big feature to implement at this late stage, at least the grid shouldn't be reorganized like this.
Anyway, I and others have been posting about this issue in the "Beta UI Wishlist" (and other threads) for a while now.
