Blacks clip on AAF import to Smoke 2012

Hi y'all, I'm a long time Smoke user (since Fire on Irix), recent convert to Mac.

I'm using Smoke 2012 on Mac, and have imported a number of Avid AAFs, in DV50 MXF & DNX 185 MXF. All are 8 bit, 25fps.

The import goes fine, I get the media, but it's apparent that it's not keeping the headroom, so blacks and whites are clipped. This is a major pita, and the headroom setting on MXF in the gateway seems to make no difference. Has anyone managed to navigate this successfully?

Thanks in advance,
Dave