A couple of ahem… hiccups have popped up for some users of VMotion after upgrading to vSphere.
The Knowledge base team has been ultra-fast in responding to these, and two new KBs have appeared:
VMotion stops working after upgrading to vSphere 4.0 (1011294)
and
VMotion stops working after upgrading to vSphere 4 with a Licensing server is not configured [...]

The new Knowledgebase blog has just posted a table of brand new (or recently updated) timekeeping articles for VMware products.  A nice one-stop shop for all the time related KB articles. Worth a visit.

There’s a new problem a few customers have reported whereby-

ESX disconnects randomly from VirtualCenter
ESX disconnects when performing VI Client tasks from VirtualCenter.
Tasks randomly timeout after a long idle time
“An error occurred communicating to the remote host” pops up.

This only refers to Update 3. This issue seem to be affecting customers with firewalls using state-ful inspection, [...]

VMware Virtualcenter roles and permissions are one of the most commonly misunderstood aspects of Virtual Infrastructure 3.  We constantly receive calls into tech support asking how-to assign the appropriate rights to users and their virtual machines, clusters, etc.
A new article I saw on VIOPS today that helps one understand some of the basic premises of [...]

If you ever have trouble starting Virtualcenter check the logs.
C:\Program Files\VMware\Infrastructure\VirtualCenter Server\Logs
Look for this message:
[2008-01-17 01:05:43.917 'App' 304 error] Unable to get exclusive access to VC repository.
This means there are some connections to the virtualcenter database (repository) that need to be freed before virtualcenter can use it. It will not start until it can get [...]