Little pause at block 1399.. Might be GAW implementing the hyperflex blockchain

Yeah, let me explain this one.
When you're trying to measure the hashrate of the network there's massive variance between block times, which makes it extremely hard to know how to set the difficulty. With Bitcoin it's averaged over two weeks worth of hashing time, in an attempt to smooth things out somewhat. Even then the difficulty can swing +-10% just from luck alone. GAWminers in their infinite wisdom made a system which uses the average of.. two blocks. What this means is that if a block is very lucky, the difficulty of the next one (and the "network hashrate") appears to be stupidly high compared with what it really is. That's why there's huge gaps, and why you'll see people on HashTalk saying that the network is up to 50Ph/s. It's not, there was just a lucky block and they're cherry picking the ones which make them look the best.
191,012,766
350,839,774
7,343,160,41
726,246,634
30,557,651
76,394,136
122,776,299
36,110,678
95,587,110
Here's a sample of the difficulties in sequential blocks. I'll let you guess which one caused the 30 minute block period.