it probably due to the recent transaction congestion, may the network become fast after SEGWIT.
Well that transaction congestion may happen if there is a server activity of the website and of course it will be faster after SEGWIT. Sometimes the most reasons were those threats from DDOS attacks which primarily disturbs the network activities, slowing connections which is so distructing to account transactions at ccex. Traders at ccex were not happy about this specially to the concerned person on this thread here.