negative scale+rotation+collider

I’m making a 2d game (unity 4.3).
I’m using localscale.x = -1 to flip the character to the other side. it works fine, the problem is, when I rotate the character while the x scale is negative, the collider2D doesn’t react very well. it starts to shrink for some reason.

When the scale is +1 it all works fine.

But I change the scale to -1, the sprite looks great, but the collider2D reacts strange and starts to shrink and doesn’t follow the sprite correctly.

Any ideas?

This is the best solutions so far:

Other possible solutions:

  1. Remove rigid body on child object (this worked for me), rigid body is causing this issue.

  2. Disable collider before changing parent, then re-enable when done.