Trying to get ricochet mechanics to work, need help!

Question

Hey, for a project I'm doing, I'm making a ricochet game with Actionscript 2.0, where the player shoots a bullet and it bounces off objects trying to hit the opponent. It's working decently so far, but my problem is I'm having a VERY hard time getting it to work right.  Sometimes when I shoot at a box, the bullet will tunnel through it, bouncing off of invisible walls on its way. I just want the bullet to bounce off of the edge all around, but it is tunneling as I'll show you in a video I uploaded. Here's the code I'm using currently, but it's having this tunneling problem.
if (bullet_fired.hitTest(boxobject)) {
                if (bullet_fired._y<=184 || +bullet_fired._y>=214) {
                    bullet_fired.diry *= -1;
                    bounces += 1;
                }else {
                    bullet_fired.dirx *= -1;
                    bounces += 1;
where 184 is the top of the box and 214 is the bottom.
Am i approaching this completely wrong or what am i doing wrong.
Here's the video I uploaded of me demonstrating my problem. http://www.youtube.com/watch?v=O9dwW4_UcFM
Please help me and give any suggestions you have, I'm pulling my hair out!!

Answer 1

you're repeatedly satisfying both your hittest and your y constraints when the bullet is shot at a shallow angle.  ie, the y-property of your bullet does not change enough with the initial hit to prevent a 2nd, 3rd etc hit.
again, to remedy, use:
if (bullet_fired.hitTest(boxobject)) {
                if (bullet_fired._y<=184 || +bullet_fired._y>=214) {
                    bullet_fired.diry *= -1;
bullet_fired._x=previousX;  // you need to define previousX and previousY
bullet_fired._y=previousY;
                    bounces += 1;
                }else {
                    bullet_fired.dirx *= -1;
                    bounces += 1;