Hi!
I got my k5 back from the servis. They say that everything is alright. They made over 200 hundred shots and there is no evidence that anything is wrong. They said that the problem is probably in the wrong memory card.
I am very happy that camera works, but I only have 3 weeks of warranty left and offcourse there is no way to buy any extra year of warranty in our country.
Thank you all for your responses, I hope your answers are all wrong and the servis is right! I also hope that StephenHampshires scenario doesnt happen to me!