I had the same problem start this week. I was out of town, so can't be sure of the exact day. But when I got back no amount of refreshing would work. But I had been stalling on rolling to latest firmware (072 I believe?) I went ahead and updated and the app is back to working again.
So are you by chance still on the previous firmware? Go ahead and do the update to the latest and hopefully will work for you as it did for me.