User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.8) Gecko/20050519 Firefox/1.0.4 Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.8) Gecko/20050519 Firefox/1.0.4 With Firefox 1.0.4 on Linux, I can start the Profile Manager while another session is already running. Reproducible: Always Steps to Reproduce: 1. Run "firefox" 2. Run "firefox -p" Actual Results: After step (2), Profile Manager shows up. Expected Results: If executed on Windows, a blank firefox window shows up. I'd expect Firefox to behave identical on both platforms. According to bug #297470, users aren't supposed to start 2 different instances of FF simultaniously, if MOZ_NO_REMOTE is not set. That's not the case on Linux. It would be better, if the Linux version of Fx also requires MOZ_NO_REMOTE to be set - or if the Windows version does NOT require MOZ_NO_REMOTE to be set.

*** This bug has been marked as a duplicate of 280725 ***