There are currently some network issues with coin switching. It occasionally doesn't switch, and hangs for 20 seconds or so. This seems to happen once in every 5 switches or so.
I'm working on a fix, but in the mean time if you want a workaround, and you can are ok with recompiling cgminer, you can:
in
https://github.com/ckolivas/cgminer/blob/master/util.cchange:
const int tcp_keepidle = 45;
const int tcp_keepintvl = 30;
to:
const int tcp_keepidle = 5;
const int tcp_keepintvl = 4;
These occur twice in the file.
Thanks to `Kevin on IRC for this.
Sorry if this has been asked but I've got far too much to do and have been reading for 2 hours now.