I have the eact same problem... I wanna play live chess with my friend, but when i click on the challenge link, i always get to correspondence chess no matter if i use the link in his profile or the link under "online friends in live chess".
how to challenge a online player to live chess?
I can't understand the creators of this chess site which is so good otherwise but to challenge a friend you have just played seems to be far from straight forward. I seem to be able to select an opponent but how I then challenge him is very unclear. Can anyone explain in simple language.

I can't understand the creators of this chess site which is so good otherwise but to challenge a friend you have just played seems to be far from straight forward. I seem to be able to select an opponent but how I then challenge him is very unclear. Can anyone explain in simple language.
Yes, that's the one reason I don't use this site as much as Playchess.com, unfortunately.

I found out how.... Both must be online at the live section, and then under "friends" you can click "play" and then the right challenge window til appear :)

To challenge a friend to a live game, you both must be in the live chess interface (play->live chess) at the same time.
There is a friends tab at the bottom of the screen.

I have read the threads but it's still not clear how to challenge a specific player to 5 min blitz if they are playing a different time control. A lot of players online are playing for example bullet. How do you get them, if they are on your Friends List, to play blitz? From what I have seen you can only issue challenges, to accept existing challenges, but unlike playchess.com you cannot challenge a specific player to a specific time control.
I have read the threads but it's still not clear how to challenge a specific player to 5 min blitz if they are playing a different time control. A lot of players online are playing for example bullet. How do you get them, if they are on your Friends List, to play blitz? From what I have seen you can only issue challenges, to accept existing challenges, but unlike playchess.com you cannot challenge a specific player to a specific time control.