Firefox - video gets rendered on top of other Flash content

Have been doing a lot of hunting around, but have not found mention of such an issue in either the Firefox or Adobe sides. The issue has been around for at least 2 years. Anyone else run into this? Any workarounds?

App Setup:

A minimally customized build of Strobe Media Playback 2.0 with the OSMFCCLib closed captioning library from Adobe (packaged with AMS) integrated. There's not much to the library and it's a black box (closed source). You just point it at the media player and container.

It's not exclusive to this closed caption use case as I've run into the problem with other stuff, but it's an important accessibility case.

Expected Behavior:

Closed captions rendered over the video.

Actual Behavior:

Works fine in all browsers except Firefox (at least in Windows).

Observations:

The video appears to get rendered on top of everything else. I've run into this with other stuff that I've attempted to overlay on top of the video. Even the built in Settings modal for Flash Player. This is what suggests a larger underlying bug with the browser and/or plugin. My guess is that it's some sort of heavy handed optimization for video rendering. Firefox seems to have a history of breaking things around FP, so wouldn't surprise me.