Bug 09. Vray 1.47.03. 32bit to chanel. opasity overbright

Max 7.0+sp1
I render scene use opasity slot in material. And save in 32bit per chanel material whit map in opasity slot. And i see this material - overbright. Using brightnes-contrast in combustion not help.

Material - standart or vray.
If i save this render to 16bit per chanell all right.

Whats a problem?