[HELP]Rip speed problem

Hi there.
I have the Nec 3500.

With original firmware 2.18, i can rip with dvd decrypter at 3/4x speed incrementeed by 0.1x every 40 seconds.

Well i tried to upgrade firmware with a modified one suggested by you.
But with every modified firmware i have a speed rip of 0.1x always.

my system:

Abit nf7-s
Barton 2600
hard disk sata maxtor 160gb

What it can be for u?

p.s. I have used binflash to upgrade firmware, and the nec is setted to primary master.