I’ve noticed that sometimes in single window mode the version of the document displayed in the canvas window does not reflect what’s shown in the layers panel - you are somehow using a cached, older version.
I’ll try and get a repeatable formula for this - it seems to happen when you have more than one file open.
To solve it I have to close and then reopen the file, after which it works as normal.
What you see in canvas window is the result of a cached render. Try to change from low res to hi res in Cairo. It is possible that the render for canvas fails but not the navigator.
-G
I don’t think that’s what’s happening here. I’ve had problems where I can do things like hide or show layers or even delete them with no effect on the canvas at all. I’m not using Cairo, just Synfig Internal.