Transform_world and motion blur

Hi!

I'm trying to apply a motion blur on one of my effects.

To do so, I use Transform_world() with 2 matrices. And there start the troubles.

The most logical to me was to set it like so:

(&beforeMat, &currentMat), //my matrices

2L, // my number of matrices

FALSE, //Src to dst

But the result is a strange blur coming from the top left corner (I assume it's a null position).

I've tried many different settings, using an identity matrix, a matrix full of zeros, even using the same matrix ( &currentMat, &currentMat)... which should give me no blur... but still the same weird result.

Anyone ever encountered this issue? Or managed to use the motion blur this way?

Thanx in advance,

François