Unexplainable prim behaviour

I wrote a script for a door, which basically works fine. The prim is resized and the position changed to slide it up and down on click.
Now, here's the weird part: the script works for approx. 20 clicks, then the doors stay in their current position. The script is still running; the integer values used to store door and material state still get their correct values, 0 or 1 (I tested that with llSay commands). The llSetPrimitiveParams command is still executed (at least I get a message when I replace it with a llSay command). Only the prims stop to resize and move.

I get no script errors. Resetting the script doesn't help. A copy of the same object also doesn't work. Only taking it up (into the inventory) and rezzing it again helps, and it works for another 20 or 25 clicks. Please, has anyone an explanation for this strange phenomenon? Many thanks in advance.

integer x=0;

default
{
    touch_start(integer total_number)
    {
        if (x==1)
        {                
            llSetPrimitiveParams([PRIM_SIZE, <0.482, 0.716, 0.01>, PRIM_POSITION, <0.3467, 0.0004, -0.4966>]);
            x=0;
        }   
        else
        {                
            llSetPrimitiveParams([PRIM_SIZE, <0.482, 0.429196, 0.01>, PRIM_POSITION, <0.3467, 0.0004, -0.7985>]);
            x=1;
        }
    }
}

Nothing's wrong with the script. It worked fine for me. The object might have gotten corrupted. When that happens copy won't fix the problem.

Recreate the object. Click on new script then paste your code in from the old object.

Thanks alot that really helped. I didn't knew prims could get corrupted. Thanks for the quick answer.