note that if this is with the ubuntu-text theme, despite your bug report showing that it's not configured, this is because the plymouth-theme-ubuntu-text only updates its string when this package is upgraded, and there has been no new package version between oneiric and precise. When updating plymouth (which will automatically fix your immediate symptom), we should probably add a trigger that watches /etc/lsb-release.
note that if this is with the ubuntu-text theme, despite your bug report showing that it's not configured, this is because the plymouth- theme-ubuntu- text only updates its string when this package is upgraded, and there has been no new package version between oneiric and precise. When updating plymouth (which will automatically fix your immediate symptom), we should probably add a trigger that watches /etc/lsb-release.