New physics creating a problem in working game.

Hey guys,

I am working on a arcade ball game.It was working fine in unity 4.6.
Once i updated to unity 5 the new physics system is causing a problem.
The ball often gets stuck on the edge of the rims surrounding the hole without falling into it.
I tried changing the physics material but this does not seem to fix the issue.
I have attached images of it. Any ideas on how to fix it?

48052-screen-shot-2015-06-12-at-123609-pm.png

Well, isn’t the obvious solution to continue using Unity 4.6…?