Hi Henri,
Looks like this is no longer reproducible on the release you did today. Cool!
Anyway... I was swamped and could not get more details until today, so here is what i found for the sake of completeness and curiosity.
This weird 'lighting related behavior' was was affecting objects attached to the hud points on my display, and yup, lighting has never affected huds in my experience. I didn't even think about it in detail till you brought it up and mentioned all the modes available in Cool.
Under the conditions noted below... turning on "Extended Environment Shaders" caused all the hud objects to be visible as expected, turning it off caused all the huds to be blacked out. "Advanced Lighting Model" had no effect regardless of if it was on or off. So, apparently i had "Extended Environment Shaders" turned off for some reason, (probably after visiting an over crowded shopping mall) and noticed the effect later.
It turned out a combination of two settings caused the weird 'hud black out' effect...
"setenv_densitymultiplier:0=force"
"setenv_sunmoonposition:0.0=force"
Strange stuff. I thought it was interesting enough to close out with the extra information.
As always, thanks for what continues to be my favorite viewer by far, and the insane amount of support you put into it.
Stay Healthy!
-Lycia