This has been discussed a little at PGLS but I'll post here in case anyone else missed it.
Two nights ago I logged in to PG and noticed that there were no players showing in the lobby. A friend noticed that I was not visible as well. The Steam friends window worked as normal (I could see friends and chat), but nothing in lobby. I was also able to play the PGLS tournies as usual except for the fact that the chat feature in-game was disabled.
So far over at PGLS there are at least 3 people reporting the same problem. Anyone else?
Perc