Are you talking about exchanges? Because the wallet work perfectly, you can try https://blocktrades.us/ for example, the exchange from @blocktrades. Is working perfectly.
Some exchanges have problem with configuration or ... sometimes they try to manipulate the market putting the wallets in mantenance mode .... yes, it happens and now that Steem is a B- (Buy the hell out of it) coin in this report could a be a good way to mantain the price down and buy a lot of it.
I do not say this is what is happening but, could be ;)