animating focus with vray physical-cam

[worldmode]

hi everyone,

i need to animate my focus from a glas, 10cm away from my vray-camera, to a total view, 500 meters away, till my camera is moving slowly upwards about 50cm.
i tried to animate the "focus distance" and my target about 200 frames. it should be a smooth focus-fade between my glas and the horizon. but what i get in both ways, is a very fast change of focus in 2 frames and a different focal lenght, wich isnt shown by a parameterchange!?
is this a bug in vray, that i cant animate my focus for a distance of 500 meters without changing my view?

i cant fix this by z-depth in postproduction, cause of my transparent glas.

here´s a preview-rendering...

http://www.youtube.com/watch?v=H7BTw1uXKbI

any ideas?

greetz, and thankfull for help!

[Slazzo]

Looks more like a wrong keyframe in focus distance or target pos, just tried with the demo version using keyframed focus distance only, works fine for me.