CAN'T BE CHALLENGED

does he get any error?

The settings he may have for ratings limit (minimum - maximum) may be out of range for your rating. Try that.

:) our ratings is quite the same

 I'm not talking about having similar ratings...

You have a "setting" of what range you will play for the game, meaning anyone out of that range will not be able to play against you. This has nothing to do with your own rating compared to the other person.

The thing is that I can chalenge him :) and at my chalenge list ikescreme always is but he cant see my chalenge if there were any restrictions i couldnt chalenge him

When you go into your online games page and you scroll down the page a little, look underneath the list of current games you have, and you will see that your friend has successfully sent you two game challenges.

Titjukaz      1421      Let's Play!      Random     3 days     
Titjukaz     1421     Expendable     White     3 days

I had found a little difficulty locating challenges in live as well. The challenges go to you but are displayed in main chat (you might need to scroll up to find them at this point).