According to https://wiki.ubuntu.com/XubuntuDapperReleaseNotes , Xubuntu needs at least 1.4 GB to install. Still, it should not crash though.
-- Crash on instaling xubuntu insuficient disk? https://launchpad.net/bugs/58651 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs