Hello Clousseau,
I don't know what you experience, but after the last update I experience there is something wrong with the stability of FF, and that is why I use Flock, no problems with Flock with the full psecurity Christmas tree installed, as stable as a rock, Sir.
With the latest Flock, it could of course be due to a corrupt dll file, I find several start ups that Flock closes because of jar50.dll problem I have, and I suspect that is in conjunction with xpcom-core.dll (that has to sort out 73 imports), then the jar50.dll and the four other dll's it calls are not in one and the same browser file as well (jar50.dll makes errors in nspr4.dll, dlc4.dll, plds4.dll, and the notorious xpcom_core.dll. See nxXPCOM_h, then the digital signature is not valid, and this SF does not contain a valid hash of the MANIFEST.MF file. For the mo I use flock or Opera. FF with NoScript is not crashing because of the bug mentiuoned in this thread.
polonus