[Gary Brauch]

Go to "Add or Remove programs" in the control panel. Click on the product and then select "Change" and then "Modify".
When it asks for a license server, you can either change it or add another one (seperated by comas).

My guess would be that it's a bad port because a reboot fixes it and usually, the MSU just dies. But I wouldn't rule out a bad MSU either.

This is an easy test and if it doesn't fail after moving it to another machine, then you'll know that it's not the MSU.