Ctexmap element brigher in 1.5 than in 1.4

[astudio]

In 1.5 Ctexmap (ambient occlusion) is very bright comparing to 1.4.1.
Gamma issue?

[maru]

Any example of this or instructions how to reproduce?

[astudio]

First one from 1.4.1 (gamma automatic) (resolution reduced)
Second one from 1.5 (gamma automatic)

I didn't change properties of dirt in AO, just installed the new version and clicked render.

If I want it looks like first one, I need to store it with gamma override = 1.0