We found it to be a waste of time and since we pay the IT by the hour, any IT staffer we catch wasting our time and money on such efforts gets scolded.

I'm sure there are IT staffers that want all ducks to be in a row but will your company pay for this? Ours will not.

With that out of the way, read http://social.technet.microsoft.com/Forums/en-US/w7itpronetworking/thread/5f2442f6-c3e9-4e09-9965-c984cfd60d22/

Remember to remove the old PC from the server first after you change the name as there is cached information.

That is, you can't just name a PC "thisoldpc" if there was another PC of that name without that deletion on the server. And yes, they covered this in the classes on Server Administration.