About bouncing balls

MarkOnTheIron

I've created a simple screen with walls on all sides and a ball that go on forever bouncing on the walls.
The only problem is that after some bounce, whatever the starting angle, the ball start to bounce orizontally or vertically. This behavior can be noticed in codemonkey's pool game and other similar projects.
Is there a way to fix it?

MarkOnTheIron

Yeah, I thought of something like this, this would eliminate the straight bouncing, but it doesn't resolve my problem.
It's possible to use a math expression that calculate the angle at which the ball should bounce and then add it in a "bounce or collide" rule?

foxnett

In my game BrickOne http://gamesalad.com/game/play/26603
I have add a watchdog: after 10 bounce without touch the bar the direction of ball change