Unable to stop or use COM+ component

I just had a really bizzare issue on my home workstation. I was having trouble accessing a COM+ component that has always worked - the error was a standard issue Access Denied. All the permissions looked fine. I thought maybe it was having difficulty accessing a file or registry key so I pulled up Sysinternals ProcessExplorer and ProcessMonitor to take a look under the hood - and then I noticed something odd: The account it was running under was showing as . The only change I had made recently was to hide the account from the Windows login screen (HKLM\Software\Microsoft\Windows NT\Current version\Winlogon\SpecialAccounts\UserList) - sure enough, after I removed this entry it worked as expected.