Flash CS4 and Onion Skinning - 6/30: More info uncovered

[Markham]

Is there any hidden settings that will cause it to turn off?  Some time today my onion skinning just stopped working.  No layers are locked, the brackets extend over multiple frames, but nothing is shown.  I've restarted Flash, I've restarted my computer, and I still can't get it to turn back on.  This is the latest version, 10.0.2, the "bug fix" version.

[edit]
It's suddenly working again... all except for one movie clip I need it for.  And everywhere else, if I unlock a layer and lock it again, onion skinning is still applied to it for some reason.  This wasn't happening before I installed the "bug fix."

[chluaid]

I'm getting some weird behaviour with locked layers and onionskinning too. Nothing as major as before the bug fixes, but still wrong. I can't reproduce your bug Markham but if I select a keyframe, turn on onionskin, then lock the layer, the onionskin disappears (as expected) but the object remains selected - you can only deselect it if you unlock the layer first. Stupid behaviour that I guess we can only work around or put up with until CS5 

[Markham]

I've found out more on this issue.

First, a video demonstrating the issue:
http://www.youtube.com/watch?v=IWD3aFMMzNw

It seems to be caused by having layers underneath the layer your working on, and having them both hidden and locked.