Glitch

1

I’ve come across an unknown glitch in the development of my game. If you check out the .swf, you’ll notice then when you move left or right in roll mode, the guy bounces. Note that while moving, the guy also rotates. Here is the code:

onClipEvent (load) {
	// movement variables
	standacc = 1;
	rollacc = 0;
	friction = 0.96;
	thrust = 1;
	// jumping variables
	jumping = false;
	yspeed = 0;
	gravity = 2;
	floor = this._y;
	// misc. variables
	scale = 30;
	Mode = "standing";
	actions = ["stand", "walk", "bounce", "slam"];
	action = actions[0];
	// initialization
	this._xscale = scale;
	this._yscale = scale;
}
onClipEvent (enterFrame) {
	// standing mode
	if (Mode == "standing") {
		// self-ran
		rollacc = 0;
		this._rotation = 0;
		if (!jumping) {
			this.gotoAndStop(action);
		} else {
			this.gotoAndStop("bounce");
		}
		if (!Key.isDown(Key.RIGHT) && !Key.isDown(Key.LEFT)) {
			action = actions[0];
		}
		// movement
		if (Key.isDown(Key.RIGHT)) {
			this._xscale = scale;
			this._x += standacc;
			action = actions[1];
		}
		if (Key.isDown(Key.LEFT)) {
			this._xscale = -scale;
			this._x -= standacc;
			action = actions[1];
		}
	}
	// rolling mode
	if (Mode == "rolling") {
		// self-ran
		this.gotoAndStop("roll");
		// movement
		this._x += rollacc;
		rollacc *= friction;
		this._rotation += rollacc*2;
		if (Key.isDown(Key.RIGHT)) {
			this._xscale = scale;
			rollacc += thrust;
		}
		if (Key.isDown(Key.LEFT)) {
			this._xscale = -scale;
			rollacc -= thrust;
		}
		// jumping
		if (Key.isDown(Key.UP) && !jumping) {
			jumping = true;
			yspeed = 20;
		}
		if (jumping) {
			this._y -= yspeed;
			yspeed -= gravity;
		}
		if (this._y>floor) {
			this._y = floor;
			yspeed *= -0.6;
			if (yspeed<=-19) {
				jumping = false;
			}
		}
	}
}
// change modes
on (keyPress "<Down>") {
	if (Mode == "standing") {
		Mode = "rolling";
	} else {
		Mode = "standing";
	}
}