Dielectic material to become black at high settings

[Korky]

Dielectic material to become black at high settings.

I want to render a glass of champagne and a display of these settings under the render (mental ray rendering image) glass is black but retains all of its reflection.

Image size
2500x2200 200dpi TIFF uncomp.
Max Sample Level 2
Mitchell 4.0 4.0
Reflections 26
Reflactions 26
Max Trace Depth 52
Shadow 3
GI
Accuracy 1000
FG
Accuracy 1000
IBL
Using HDR

The rest default.

Lighting, two Area Light, photons do not use

When the value of Max Sample Level 1, everything is fine

Thanks in advance

[Puppet]

Bart, do you remember I and some another user had same issue 2 years ago?

[Puppet]

Here is old thread:
http://forum.mentalimages.com/showthread.php?t=5726

[Puppet]

One more new thread regarding this issue:
http://forum.mentalimages.com/showthread.php?t=6458

mental images, where are you?