[help] slowdown in pre?

Hi all! I have got some weird problem.. After I jump and start prestrafe to jump again (on climbing maps) I have a "slowdown" in the pre and I can't jump every block succefully. How can I remove this problem and get better time?

P.S. I have demo how jumping on kz_cliffez but I don't know where to upload it. Tell me some site to upload my demo and you will see my problem if you don't understand me now.

Sorry for my bad english!

Here: http://www.sendspace.com/file/t7caqh
I know I am not good jumper, but with slowdown I am fully noob =D