In profile/dirserviceprovider/src/nsProfileLock.cpp,
nsProfileLock::LockWithSymlink() firefox tries to resolve the
hostname (PR_GetHostByName) and uses the resulting IP address for a
symlink used for locking. That causes DNS timeouts on systems where
the hostname is not resolvable such as laptops.

Looks like the code is more or less obsolete so it could probably
removed completely. It could not have worked properly in the past
either since openSUSE typically mapped the hostname to 127.0.0.2. So
IsSymlinkStaleLock() would true on all systems that share the home
directory.

If you don't want to remove the code you could use getifaddrs()
instead to find the systems' IP addresses. getifaddrs() doesn't use
DNS therefore doesn't cause timeouts.

See also bug 383336 for a lengthy discussion about unecessary dns timeouts.