I have a similar problem with my minting node, no longer able to generate valid blocks since 7/3/17. Nothing changed, same computer, same network. Just restarted the lot, still same problem. Also unable to use the new client, this results in blkindex issues after a few blocks. Tried everything to no avail. It is connected to 8 other peers.
I suspect the recent fork has something to do with all this.
Blockexplorer is also down. Things are going downhill quickly in the last few days. Not good.