Changing a body's type causes it to ignore collisions for a few steps

What steps will reproduce the problem?
1. Create a static body (let's call it BodyA) and position it such that it's 
"resting" on another static or kinematic body (BodyB).  Make sure there is 
gravity or some other force being applied downward.

2. Change the body type of BodyA to dynamic

3. Observe that BodyA will fall through the static body.

What is the expected output? What do you see instead?
Expected output is that BodyA will continue resting on BodyB.
Actual output is that BodyA seems to ignore collisions for a few steps, and 
falls through BodyB

What version of the product are you using? On what operating system?
r141 (latest as of 12/31/10)

Please provide any additional information below.

see http://box2d.org/forum/viewtopic.php?f=8&t=6010 for more info

Original issue reported on code.google.com by aaronpen...@gmail.com on 31 Dec 2010 at 8:18

behdad / box2d

Changing a body's type causes it to ignore collisions for a few steps #169