We have 2 users on our Mac - both with admin rights. We can both log in and out fine, and our names both show up on each log in screen. However, when trying to shut down the unit, the name field is empty. We enter our names and passwords, and are told 'invalid user name or password.' This may have happened after we upgraded from Tiger to Leopard Mac OS X 10.5.2, but I can't say for sure. Thanks in advance for anyone with any tips!