There's a long standing bug (or perhaps an oversight) in most *coin code where peers on an older fork will repeatedly ask for the same set of blocks from those on the new/current fork. Neither the requesting peer, nor the sending peer, have any code to check for duplicate requests, so they just continue in an endless loop, requesting and transferring the same blocks, over and over. That is most likely why your client is using a lot of upload bandwidth right now.

My ADSL is 1:20 Mbit/sec upload:download, so a single coin with forked peers can saturate the upload side, and slow the entire link. I've disabled HYP for the moment.