Ic-racer, that's basically the test that I did, except for the measuring of density with light meter (I did it by looking at zone 0 which should have no density) and for the zone VII (I used zone IX to determine the dev time).

Matt, yes that's possible. In fact I meant density, not fog. These are two different things, right ? Your 2) point is what I think is happening, that zone 0 received light when it shouldn't have.

Silveror, shutter speed were checked a year ago so they should be ok.