Mask motion blur angle and phase

Hi guys

I'm working on a project where I need to rotoscope a bank card to change it's color.

I've made the roto in Mocha and transfor it into a mask.

I've added a motion blur in the mask settings, it works fine but ... the angle and phase are wrong.

I went to the comp settings to change it but it seems that it doesn't make any difference.

It works with moving objects created in Æ but it doesn't with masks

Any idea?

Thanx