Alpha Problem?

I seem to be having a problem with the alpha setting of a sprite that I create. When I use the code below the line is completely invisible, if I set the alpha to 55 it is visible. Can anyone help me see why I can't make it lower?

bmap dot_bmp ="dot.bmp";

function delete_line()
{
my.alpha - = 5*time;
if(my.alpha < = 0)
{
my.lifespan = 0;
}
}

function draw_red_line()
{
my.bmap = dot_bmp;
my.move = off;
my.streak = on;
my.bright = off;
my.transparent = on;
my.alpha = 50;
my.size = 0.25;
my.function = delete_line;
}

Why are you using particles? You can emulate draw_line3d by using draw_line and vec_to_screen.

Quote:

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Why are you using particles?

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There are plenty of reasons why he'd use particles over these functions. If it's a laser beam, or a smoke trail. If it's just a line, I agree, use those other functions.

As for your problem, wow, that is really strange. I can't see anything wrong with it. If no one else points anything out, I'd post something in the bug hunt forum (along with some screenshots of both alpha = 50 and alpha = 55).