1.46.04 new transparency settings?

i tried to render a scene with 1.45.70 and 1.46.04 and the transparent parts seem to react in a different way.

does it mean i have to redefine all the glas parts? what has changed?

the middel image is the difference of the 2 renderings.

also the render time increased about 5%
a full res image went from 3h12min to 3h23 min

btw: DR really rocks, chaosguys!