Hello, First off all it was tested on a new profile with the following configuration: User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20100101 Firefox/13.0.1 Reproducible: Always When setting history settings to "Use custom settings for history", if I try to add the IPv6 address [::1], it create a new entry with the name: ':'. (Cookie selection are not applied when browsing [::1]). If I try to add [2001:db8::1], nothing happens whatever the status I choose (selection remains in the "Address of website" input field). I did not found anything relevant in an env with: 'export NSPR_LOG_MODULES=all:4;export NSPR_LOG_FILE=~/cookies.log'. It could be related to bugzilla entries numbers 633001 and 359106. It seems to be related to IPv6 addresses parsing.