User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; de; rv:126.96.36.199) Gecko/20100504 Firefox/3.5.10 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; de; rv:188.8.131.52) Gecko/20100504 Firefox/3.5.10 I'm using a "mozilla.cfg" to lock serveral Preferencies. For example: lockPref("browser.formfill.enable", false); When I open then Preferencies Menu, the Option is set correcly to "false", but it is not grayed out. When I click the Option, it get's grayed out. I then switched the Option to Start Firefox in Private Browsing Mode two times and the above Option "browser.formfill.enable" was no longer grayed out. Works as designed? Reproducible: Always Steps to Reproduce: 1. Start Firefox in "normal" mode 2. Open Menu "Perferencies" 3. Check Option "browser.formfill.enable" as set by "mozilla.cfg" - Option is not grayed out. 4. Switch this Option once - Option is grayed out. 5. Switch Option "Start Firefox automaticly in private mode" (don't know the correct expression, I have a german version) twice - the Option "browser.formfill.enable" is editable. Expected Results: 1. Option "browser.formfill.enable" is not editable when opening the Preferencies Menu. 2. Switching the Option "Start Firefox automaticly in private mode" does not make "the other" Option editable. I noticed this behaviour for other preferencies too.