I was scanning some ilford HP5 negs (v700) when one of the squares refused to give me the correct colour, ie, it kept the brown tint in had in the preview. When I tried to correct it using colour balance in PS, it was left with a funny green tint.
I then tried scanning the neg with a normal flatbed, then inverting it and playing around with the brightness/contrast. That created a decent scan.
I've posted the photo on and the original v700 scan (post PS) is in the comments.