And to have higher BID as ASK must be an error.

Yeah, but this is just data from mtgox API. There's a lot of fun stuff there. ...

Thats interesting! Is this intentionally done by mtgox, to disturb trading bots and scalpers etc?

I very much doubt it. I think they just suck.

I am not sure! Clark (http://bitcoin.clarkmoody.com) has other experiences:

Whenever I receive a trade, I make sure the book doesn't have incompatible orders on it. This, in effect, keeps the book from being crossed.

Thanks for reply.
But does the mtgox orderbook has crossed orders, or are there crossed BID-ASK quotes via API?

When Gox detects a crossed book, it halts trading and fixes the problem. So the answer is no.
https://bitcointalk.org/index.php?topic=43514.msg3153629#msg3153629