Flash elements intermittently not loading on linux + firefox 3.0.1?

We are in the final QA phase of our new website, and everything was looking great until yesterday. Then, I noticed that some important flash elements were sometimes loading and working correctly and sometimes not - they actually would load, but the area they loaded into was just gray. It was seemingly completely random when the elements would work and when they would not. So troubleshooting time.

We saved out the flash in downlevel versions all the way back to 6. No luck. We changed the way we embedded the SWF from using SWFobject.js to using Object/Embed tags directly. No Luck. I tried changing the flash plugin from 9.0.0.115 to 9.0.0.224 No luck. Tried the beta of the 10 plugin (wayyy too slow). We tried accessing the swf directly - same problem. Then we tried a swf that we pulled down from Adobe's website. WTF?!? Same problem. We tried serving the code from Apache and IIS. Nothing.

So I determined it had to be something client-side and reviewed my yum updates from the past few days. I noticed a package called nspluginwrapper, and I remembered having some problems installing it when it initially appeared in updates. So out with that package: rpm -e nsluginwrapper (it was version 1.1.0 release 4.fc9)

And voila. no more flash problems!