I have 32 bit fedora 10 on a 64 bit system. I am working on the multimedia portion of a Windows to linux app port, which is why I noticed these problems. Others have skirted this issue but haven't quite identified the fundamental problem. I don't really know if this question should be posted in mozilla or here.
I ran the suggestions posted by leigh123 to remove nswrapper and flash and then re-install. Well, it did remove both (and emptied my pluginreg.dat file) but the re-install did not restore the FF plugins, though yum, rpm and add/remove software all reported that the latest Flash is installed. I also downloaded and ran the dangermouse utility. That restored the nswrapper libraries and put a whole bunch of stuff back into my pluginreg.dat file, but I don't believe that they should be needed.
Where do the nswrapper_32_xxx plugin libraries come from and what is their purpose? Is that the app from Gwenole Beauchesne? There is one for Flash and one for the PDF/FDF viewer. Adobe has released a perfectly good Flash plugin (even a 64 bit beta version). These libraries simply seem to get in the way of the Adobe libraries. I have written code to parse the FF pluginreg.dat file, load and execute the proper plugin based on the input file extension and MIME type. My code fails on these libraries but not when I directly load the Flash plugin.
Thank you for any help understanding what is going on.