i've edited my prefs.js file (without mozilla running) because i wanted to change my cache location. i added a new cache location on drive C: and made sure the directory existed, then saved the prefs file. on the next run, mozilla does not use the cache directory. it creates a directory called NewCache on my profile drive and uses that. it does not update the prefs.js file to the new location; my chosen cache is still shown there, but it is not used. the benefit of having this approach be allowed is pretty easy to see... i have a networked configuration with a local cache. when mozilla has the cache on the networked profile drive, it is very slow. i used to be able to move it to drive c:, which makes mozilla run a lot faster. that ability disappeared a few revisions ago and the cache config item is now being silently ignored on startup of mozilla. it seems like the fix would be removing whatever special logic is ensuring that the cache drive and the profile drive are the same. i don't currently see any reason why those would need to be on the same drive...

Dup. *** This bug has been marked as a duplicate of 78480 ***

VERIFIED/dupe