I faced the same issue. I was using Panasonic MV-FS200 (which was thought to be the issue in another topic), but it seems like those lines were on a tape before (at least on my old captures i can see pink tint on some surfaces as well).
I took a closer look at interlaced footage and noticed pink lines are at odd fields, and they present all the time, just their intensity can change frame by frame. After deinterlacing (with QTGMC) they look like pink flicker (shimmer) when one frame is ok, and next one has a strong pink tint to it.
I did test the script, provided by themaster1, it made those lines kinda more blurry, but they are still there.
I'm attaching a piece of original capture, where its best seen (look at white walls). I noticed slight pink shimmer after deinterlacing on other captures (also noticed it on wall surface), but it wasn't that strong as on this capture. Also attaching processed capture, and a screenshot of close up of those lines (i added contrast and hue to make them more visible to the part of screenshot).
The noise filtering in the LSI logic chips is only active when encoding to mpeg2 as far as I know. At least on any of the PAL ones I've used. The Video decoder chip is separate from the LSI system/mpeg2 chip, and varies between models. Not aware of any LSI-based ones that use one that can stabilize jitter like panasonic chips can either. Some use Philips/NXP chips which are good at not loosing sync, but do little horizontal correction, the jvc ones use some custom jvc chip which also does some mild jitter correction, and some use TI chips that dont handle unstable video well at all.
If it's some signal issue rather I suppose it's possible that a different A/D chip would be able to reduce it, but it depends on the source.
I made some research, and found a possible solution. It was suggested to try loading video using DirectShowSource, i was using FFMPEGSource2, and did try AVIsource, both gave me flickering after QTGMC. DirectShowSource didn't give me flickering, at least wasn't noticeable by eye.
Regarding pink scanlines, they are written on tape and not a part of a playback problem as far as i can tell. They appear on some surfaces for me (like walls or sky), that pink hue is sometimes very noticeable, and that i would correct later.