Villa and Valdes, Disappearing Acts?

During this transfer season FC Barcelona's striker David Villa hasn't hidden his desire to play for another team. Yesterday it was also reported that Barca's goalkeeper Victor Valdes won't be renewing his contract with the Catalans.

 I understand David Villa's situation since he is a very good player that still always gets outshined by Lionel Messi. With all the other Blaugrana strikers fighting for a place in the line-up it's no wonder that Villa wants to play somewhere he gets regular playing time and a secure place in the starting line-up. 

What I don't understand is why Victor Valdes wants to leave. He has often been considered the weak link among the amazingly good players at Camp Nou yet he has still always been the number one goalkeeper in Barca. I mean I love Valdes, but I have to admit that I've hoped several times that Barca would have someone a bit more secure between their goalposts. Sometimes Valdes is great, but then another day he might screw up a situation that definitely shouldn't cause any problems to a goalkeeper on his level. I just wonder what more can he want than a secure position in the best team in the world? And the big question is that if Valdes goes, who'll replace him? Barca's current second goalie is Jose Pinto, but I doubt he'll be up for the task. Probably they'll need to buy a new one, but who will it be? Only time will tell...