Phoronix says that Ubuntu 10.04 was hit by a major bug on launch day. Apparently there is an issue with not being able to boot to another OS once Ubuntu 10.04 is installed. The Ubuntu developers and the folks at Canonical are working on the problem now.
Last week they were then hit by a serious memory leaking issue within the X.Org Server, which fortunately has now been fixed in time for the release. But now we are onto a new issue. Rather than the Canonical crew and Ubuntu developers around the world spending today celebrating the release of Ubuntu 10.04 LTS, they are busy re-spinning some of the ISOs due to a new "critical" bug.
For more details check: Operation Management Service Video