To gain the full resolution range select Square Pixel Type in the output video and not Original Pixel Type (Letter Box/Pillar Box), as your videos are PAR: 16:15 and not Square Pixel (PAR: 1x1).
The other option which i find is better is to convert your video to Square Pixel (PAR: 1x1) 1st using Hybrid tool.
Follow this Post (the part that talks about deinterlace / Square Pixel).
I would also advise not to upscale to 1920x1080, but to 1440x1080 (x2) as it is more natural for 4:3 aspect ratio of PAL DV.
Also I found for DV (PAL i tested), the best upscaling AI is Dione: DV. it surpass all the others.
