BURST coin was ddos attacked a couple of weeks ago, the blockchain/miners/pool have been struggling to get it back up.
Regarding polo, stop using that scam service. I have lost so many coins i stopped counting. Of course i have opened support tickets for all my lost coins, but they have been opened for more than 2 months now.
That's very said that there was a ddos attack. However, why do you say this coin is a scam? I recall it gaining popularity about half a year ago and a nice casino btcdragon starting to use it.
Oh, I got it, you meant poloniex is a scam thing. Well, this doesn't sound reasonable enough, for it is a very famous exchange site, but these kind of sites have problems from time to time indeed. That's why I prefer using wallets, not exchanges.