Minerva, the ISP of ISOC has been alerted and are working on the problem but cannot locate exactly where is the problem, if you have any information on where ECN packets are discarded please provide this information to support@minerva.net add [HelpDeskTicket=12181] at the end of the subject.
I think you may have more tools htan me to locate the faulty router/firewall/host?
Thanks for helping locate the problem.
Cheers
franck@sopac.org