Problems loading Italian PCN arial images

I have recently logged some gpx tracks in Italy which I would like to use in JOSM now. I discovered there are superb aerial images from “Portale Cartografico Nazionale” which are essential e.g. in towns with narrow streets where the tracks will always lack accuracy. Sadly though, the images loaded fine when I tried it first, but now I receive 403 forbidden errors from the server (red “error” images in JOSM).

Anyone (possibly with more profound knowledge either of JOSM or capable of Italian language) who has a clue what I can do about it? Just wait? Set up another internet connection to receive a non-static IP that is not yet blocked? And can I configure JOSM to minimize the chance to get blocked again (e.g. more disk space for caching)?

Have you tried emailing the talk-it mailing list?
There’s plenty of discussion of PCN on there - I’m sure someone will help.

Thanks csdf, I have already tried to follow the PCN related threads on the Italian mailing list. There does not seem to be any ultimate solution yet, but luckily my IP has been unblocked today. Before loading more PCN images again, I am now trying to trigger more caching within the WMS plugin. Seems tricky to get it to reuse its cache between sessions.