Meet the log error navigation.
Basically the idea is to show back/forth arrows only on hover and make them pull next error to the spot where the cursor is. So to hop through errors you would just go click-click-click without moving the mouse.
This compliments well existing feature of jumping to the first error of the last run by clicking on "Xxx errors" in backup's main window entry.
As per previous post, this leaves a question of how one would get to the *nearest* error if none is currently visible and the answer is that one would simply use conventional scroll for that.
All in all, having played with this for a bit I think it's a good solution. If it doesn't seem like one to you, give it a try and it will grow on you.