The Dink Network

I was just adding some new graphics to de dink.ini, it is a brain 10 (vertical and horizontal direction) wurm, kinda like the pillbug, no attack sequence, just walking. Now, I typed the following in the dink.ini:

//wurm walking

load_sequence graphics\foes\wurm\w01w2- 851 75 106 120 -41 -18 41 18
load_sequence graphics\foes\wurm\w01w4- 853 75 103 113 -38 -18 38 18
load_sequence graphics\foes\wurm\w01w6- 855 75 116 111 -38 -18 38 18
load_sequence graphics\foes\wurm\w01w8- 857 75 105 100 -43 -18 43 18

And this is in the script:

void main( void )
{
sp_brain(&current_sprite, 10);
sp_speed(&current_sprite, 1);
sp_exp(&current_sprite, 3);
sp_base_walk(&current_sprite, 850);
sp_touch_damage(&current_sprite, 2);
sp_hitpoints(&current_sprite, 7);
preload_seq(851);
preload_seq(853);
preload_seq(855);
preload_seq(857);

if (random(2,1) == 1)
{
sp_target(&current_sprite, 1);
}
}

Now for the problem: The wurm walks, but when it walks, let's say, up, it shows the animation for walking to the left (for example, there is no fast pattern in here as far as I can tell).

Can anyone spot what I've done wrong?