Comment 4 for bug 344810

If you have enough RAM you should copy the contents of .mozilla to a ramdisk and then mount it to .mozilla. Exactly this should do a script at startup. And on shutdown the script should copy back the contents to keep the changes. Please try the script attached and report any problems/success.
Just copy the script to /usr/local/bin and call it using sudo.
ffcache2mem.sh 1 activates caching to ram (need more than 50MB of RAM)
ffcache2mem.sh 0 copies the contents of ram back to the hd/ssd.
ffcache2mem.sh d drops the ramdisk.