Also getting a high reject-count (roughly 25% on both machines) coupled with periodic disconnect messages. Running on Ubuntu (both native & in a Win7 VM). Tried several of the servers.
accepted: 8138/8319 (97.82%) for me on the local connection, so I think 502 is related to yac.dontmine.me and mineyac.dontmine.me , try mineyac3 it's not cloudflare
ok, set one of my machines on mineyac3, lets see if it gets a better accept-rate.
The accept-rate was fine a while ago though, not sure when it started precisely.