Gary, I do indeed use a presoak. How interesting. I can't imagine at this time how that would result in those lines, but I will process my next batch WITHOUT a presoak and compare.

One reason I presoak, even though I know Ilford does not recommend it, is to rinse off most of the anti-halation coating. I use replenished XTOL a lot, and didn't want the contamination from the dye. I don't know if it would adversely affect anything, and I could always filter the developer before re-bottling.

I'll update the thread after my next developing session in a few days.