crushed blacks in AP

[keypix]

Hi.

Using a calibrated iMac, has anyone experienced crushed blacks in deep shadows? 

I've attached a screenshot showing the same file in AP and Capture One.  If you look carefully it's possible to see that AP is crushing the blacks, whereas there is still detail visible in Capture One. (I get the same difference with Photoshop).  

Many years ago I used to see this problem with Aperture, it never played well with V4 colour profiles however this is not the issue here. 

Does anyone know whats causing this?

Thanks

[Callum]

Hi Keypix, 

If possible could you provide a copy of the image in question? This will allow me to investigate this further if you would rather not post it publicly let me know and I will provide a private link

Thanks

C