Same here. Selling is also a problem. I wanted to sell some BTC at a price that was in the order book (the price that you automatically get when trying to sell) and the order wouldn't get filled. I also get a 10 second freeze or so after placing my order. This is very strange and I just lost the chance to make a bit of profit. I also tried to buy BTC at below market value and below some of the first orders in the order book and my order wouldn't get filled. This cost me some 140 EUR in profit and now I lost like 60 EUR.
I know it's small change, but hey, it's still something.

I've been having a hell of a time trading. As said, I've seen orders in the book that I try to sell or buy from and they don't go through. I even just had a limit buy order in that showed up on the book, then a minute later a big sell came and pushed right down through my limit buy order. Then I see my limit order is gone and was never even filled. It's like they have those fucking bots jumping in front of you at all times, then when it's not going to work out for them they cancel your shit.