fucked up pre

Hello, when I am doing Prestrafe... it fucks up !!!
Hmm I cant explain it in english what my problem is but here is a demo.
Hope so that u cant see what i mean

http://rapidshare.com/files/140099405/pre.dem.

i always made the pre like in the demo and i could jump 250 plus :X and now this...

but... i run (right pre ) i use "w" and lil bit mouse left
then w+d