Golfball sphere collider "Hops" over vertex-joined planes at intersection?

I have a simple sphere collider and a number of miniature golf course 'tiles' with very basic geometry. The ball appears to be hopping over connections between the tiles and getting stuck/rolling against other seams in the tile.

I have standard gravity (-77 on Y). The golfball has a small mass (experimented with ranges from 2 to 4) and both Drag and Angular Drag are set to 0.1 on the rigidbody.

I'm getting the ball to move by using .AddForce to the ball's rigidbody. The code is provided in this thread with no adjustments to the default settings/values: http://forum.unity3d.com/threads/drag-shot-mover-get-your-physics-objects-moving.86472/

The ball moves normally over terrain without incident. Friction slows it down normally and it responds to hilly terrain as I would expect.

The problem arises when I am trying to have it move over or between the golf course prefabs.

I use vertex snapping to ensure the floor/ground planes are level. The tiles are of virtually identical size, using Mesh Colliders identical to their model mesh. Yet, when passing between these meshes, the golfball appears to visibly 'hop' and when going over individual seams/lines, the golfball seems to react. In particular, when on an incline, the ball rolled downhill a small amount and when it came alongside one of the lines, it rolled slowly alongside it rather than continue downward.

I've researched the issue without success. Any suggestions would be appreciated.

Joseph.