Firefox won't flash-fallback with mediaelement.js if mod_deflate is enabled

It took a lot of investigating to find out why Firefox wouldn't do a flashfal开发者_开发百科lback with mediaelement.js - I tried on numerous servers and found that servers with mod_deflate enabled cause this issue. I toggled mod_deflate off/on proving this to be the case. In Cpanel, I'm toggling the Optimize Website -> Compress all content.

Now the question is how can I leave Compression on (because it makes the site faster) and still get flash fallback to work in Firefox?

Update: it appears that FF doesn't like a mod_deflated (gziped) .mp4

It seems that mediaelement.js also has problems with gzipped mp4 videos in IE9. A quick fix would be to disable mod_deflate for mp4 files.