Little question about Azureus

I'm downloading torrents with Azureus since one year now. Everything was ok. I can download what i want without any great problem.
The only problem that I have is that, every 20 seconds, protocol traffic take all the upload for 2 seconds. This has as effect to stop all data upload and so, limit my download to 0 every 20 seconds. This is quite boring.
I think the problem come frome 2.3.0.x version, but i'm not sure of that.
Someone else has the same "problem"?
Idea from where that come from?

Thx


Edit : I've resolved the problem. It seems that using I2P and Onion Router network were the cause of the problem --> Desactivated