Is bullet really frame rate independent?

Hello,
while I was fixing the character control for my game I noticed that his forward speed was changing according with the framerate, so I’ve asked a friend of mine to limit his project’s fps to 5 and tell me if he was experiencing the same issue, and he was.
So, he decided to write a testing code with just a rigidbody for see if we were both making the same mistake, but also the test presents the same situation.

You can download the test from here: 5fps - 100fps . Source here: http://pastebin.com/7ekCj6LL

Of course 5 fps is a very low framerate, but the difference is noticeable even from 40 to 100 fps.

I have read in this forum that bullet is framerate independent so i was expecting to see the rigidbody lagging and “teleporting”, but reach the ground always at the same time.

Have i misunderstood?

Ok, by rereading the documentation, I found this method setMaxSubSteps(int) that solved my problem.