certain tracks won't mute when I solo others?

[c-post]

I am mixing a film in Dolby Stereo, so I have an LCRS I/O configuration. A strange problem cropped up. When I solo a channel, I can't get certain other channels to mute automatically. The solo isn't pure. There are some other channels that refuse to turn off, and the solo button on the offending channels is a slightly darker shade of grey, and the mute button graphically doesn't highlight. Is it possible those channels were inadvertently made "solo safe" by me? If so, how do I undo this? I haven't run across this before.

-John

[Redbeard]

They are solo safe. Hold command and click on the solo button to turn on/off solo safe.

[John E. Walker]

Check your VCA track. I had my VCA in solo safe, which made every track in the VCA group to be solo safe without greyed out S buttons. Fooled me for a week. Haha!