AI Thinker A6 gsm module - many problems

Another problem. When I send GET to data.sparkfun.com everything is more or less ok, but when I send GET to wunderground.com, server returns "success" but gsm module stops responding after that and has to be hard reset. The function that sends GET is the same for both servers the only difference is the text string that is being sent to server. What a piece of crap, save yourself a trouble and don't buy it.