After a session using a sandboxed Firefox I can close the active application but Fx remains in memory indefinitely. If I try to open a new instance of Fx, a message tells me that it's already running and needs to be closed. The only way to remove Fx from memory is by ending the process via Windows Task manager. This does not occur with an unsandboxed Fx which closes quickly and cleanly. Running Windows XP Pro SP3. Any advice would be appreciated.