Firefox3 cannot save settings

Although firefox3 has been launched for so long, it feels much worse than firefox2.

Today, I don't know what's going on. firefox3 has crash again, but this crash is very strange. When I open it again, Firefox seems to have just installed it, all the previous settings are gone and depressing. In desperation, I reset it. As a result, after restarting the browser, I found that the settings were gone and I was speechless. I searched the internet, it's hard to find a related article about the PRE in the configuration folder of firefox3 (User Directory Application Data/Mozilla/profile/Under drive C. the JS file is related to a process that occupies this file. It cannot be deleted, and it is messy. You can't see anything with unlocker. However, a file named invalidpre. JS is found in this folder. I deleted him directly, and the result was good. It seems that this file is a ghost. When Firefox is started, it will detect whether the file exists. If so, it will restore the initial settings ??

I cannot confirm this.