Update:

re. 5 to 10 times more outgoing than incoming traffic on relay : 6AD7A3E682FE74BDFE34AC0F0D17714480BA773B

About an hour after the large difference between incoming and outgoing it had quietened down to about 7MB each way.

By two hours after that it is up to around 20MB each way - so I guess it's sorting itself out. I'd be interested if anyone has any idea what happened, though.

thanks,

Pete