Something is interrupting your connection to the server. Unfortunately, it's hard to say what. There could be a bottleneck or problem with your internet connection, the upstream routing of your data along the internet, or with the PL server itself. I also sometimes see delays and spikes. Sometimes my internet connection seems overall slow (i.e. everything I do is slow) but more often it seems to be just PL that's slowing down. It seems like the PL server itself has more slowdowns like this than it used to in the last month or so. At least that's what it looks like to me.