Well.. i finished the quest "Blood in the Ice" so why Jorleif (Ufric's Steward) won't let me buy this house ?

I had to wait till I finished the Stormcloak quests before I even got the option. I'm not sure if thats for everyone, but thats how it was for me.

Civil War quest line. Try getting through it. The entire thing is bugged as you probably know, so I'm not sure if you should really waste your time xP but it's up to you. Lol

Yeah, people said to me that it's bugged, so i will not buy it anymore.