OK, that is, the download troubles are still not over. That must mean that Krembil’s infrastructure can still somehow deal with the uploads which they are receiving, and only the downloads have the high error rate.
Sounds like it’s better to either _not_ abort them (instead, let BOINC continue to retry until the tasks time out), because the BOINC client does not request more new work from a project at which it has stalled downloads. Or to set WCG to no new work and check back again in a week or so.