elance - account blocked without explanation

I though Elance is really good site for freelancers. I has lot's of projects for everyone. I have full-time offline work, so I did bids only if project was interesting to me and I was 100% sure that I can do job perfectly.
My activity on elance was not high - not so much interesting projects, but all of my clients were happy, rating 5.0.

Suddenly I got an e-mail - my account is blocked.

"Unfortunately, your account was found to have a high number of negative client experiences when compared to other freelancers, leading to a satisfaction level significantly below the average. As a result, your account has been closed."

But, again, my rating was 5.0 - it means NO negative feedback from clients! Where this "high number" comes from? Maybe my account was banned because of rules violation? I have checked them several times. NO, I did not violated rules, I am sure.

At this moment I was sure - my account is blocked because of some mistake, and wrote an e-mail to support. My explanations were convincing enough and my abuse was taken. Few days later I got the answer

"Thank you for contacting us. Your account was carefully analyze by Elance management and team members. Public feedback is just one input we evaluate, we also look at work history, job cancelled , disputes, and other client inputs. I regret to inform you that based on this review, your account is permanently closed. "

But I have positive work history, no canceled jobs, no disputes.....

So, I conclusion, my account is permanently blocked, and they do not want to explain why....

At the moment of blocking there was no money on my account, I did not lost money, but I am sorrowing because of time spent....
And I am really disappointed.

Why it happens? I have no idea.... Maybe they are reducing competition level for freelancer from particular countries. Or they want only very active workers, who makes lots of money. Or some of competitors has sent lying e-mail to support....

Freelancers, do not repeat my mistake - do not spent Your time for elance - You can be banned without explanation.