The Dink Network

Scratcher is right, this is how the script should (roughly) look like:
(Bold commands are added, ones in italics are moved)

//Do the freeze before the fade down, so the player can't move while the screen fades:
freeze(1);
fade_down();
wait(1250);
say_stop("text", 1);
sp_x(&dbotm, 200);
sp_y(&dbotm, 35);
sp_x(1, 250);
sp_y(1, 35);
wait(1500);
say_stop("`%text.", &dbotm);
wait(250);
say_stop("text", 1);
wait(500);
say_stop("text", 1);
wait(250);
say_stop("text", 1);
wait(750);
&player_map = 621;
sp_x(1, 555);
sp_y(1, 120);
wait(500);
&strength = 0;
&defense = 0;
&magic = 0;
sp_nodraw(1, 1);
script_attach(1000);
load_screen(621);
draw_screen();
//freeze won't survive a screenchange:
freeze(1);
int &fall = create_sprite(555, 120, 0, 44, 6);
int &steve = create_sprite(80, 110, 0, 383, 1);
wait(500);
say_stop("`0text", &steve);
wait(750);
fade_up();
//unfreeze if neccessary:
unfreeze(1);
//Don't forget to kill the script after you did a script_attach(1000):
kill_this_task();

Oh, and why you did a wait(500); after changing the &player_map value is beyond me. Couldn't you just do a wait(1250); after the last text?