Why do more empty, localstore.rdf and perf.js files appear in my profile everytime I open and close Firefox?

Question

I have hundreds of empty localstore{xxx}.rdf and perf{xxx}.js files in my profile folder. Where {xxx} denotes a number. New, higher numbered files appear every time I open/close firefox. There ate two pref files (perf.js and perf1.js) which are not empty. There is one localstore.rdf file which is not empty. All other files are zero byte files.
Also, my toolbar customizations will not stay put. I have to re-customize the toolbar regularly. Erasing all of the localstore and perf files in case of a corrupt file does not help.

Answer 1

That suggests something is preventing Firefox from modifying those files. This usually happens when anti-virus software keeps a lock on the files.
''localstore.rdf'' is the file that keeps your toolbar customizations. Since Firefox can't modify it, your toolbar customizations are lost.
* [[How to fix preferences that won't save]]
* [[Profiles - Where Firefox stores your bookmarks, passwords and other user data|What information is stored in my profile?]]
A less likely cause is a Read-Only attribute or permissions issue.
* [http://windows.microsoft.com/en-us/windows/what-are-permissions What are permissions? | Microsoft Support]
* [http://windows.microsoft.com/en-US/windows-vista/What-is-a-read-only-file-or-folder What is a read-only file or folder? | Microsoft Support]