Re-centering negative frames

[pbungart]

When I scan negative strips, it seems as though the very left side of the frame (perhaps just a few pixels) is being cropped, while the right side of the frame comprises the thin border between frames. Is there a way to fix this?

[ilyons]

You need to put the negative into the carrier such that when the hinged top is closed you can slide it back and forth so that the frames are centred correctly.

[pbungart]

I think I should clarify. The problem is not the negative is not centered in the carrier, but rather the frame of the carrier seems to be slightly shifted, perhaps only 1 or 2 mm. At least that is how it appears in the preview window. I didn't notice this until recently. Perhaps this is normal? If not what causes it, and can anything be done about it? The actual scans seem to be very nearly full frame.