Dual-boot (Guest/Native) Windows XP: Login/Logoff Issue

[s34gull]

I have a Windows XP installation (/dev/sda1) which is primarily executed as a VirtualBox guest (3.1.2). In this capacity I have no issues. I have the occasional need to run Windows XP natively, and as far the boot sequence goes, everything seems to proceed normally, and I am presented with the CTRL+ALT+DEL login prompt. When I enter my credentials and proceed to login, I am presented with the "Logging On..." modal dialog, but then am immediately presented with the "Logging Off..." modal dialog which sends me back to the login prompt. Nothing interesting is in the event log - other than the inability to start DCOM (10005). When I re-execute Windows XP as a guest, everything is fine.

Has anyone else experienced a problem like this?

Regards,
s34gull