There seems to be a co-existance issue between Password Safe and the Windows CardSpace UI (installed with .NET Framework 3.0). On my Windows XP SP2 machine with Password Safe v3.01 running, double-clicking the Windows CardSpace applet in the Windows Control Panel shows the CardSpace UI for a second or two before switching back to the user's desktop. Double-clicking the CardSpace applet thereafter produces the following error message, "An error occurred accessing the Windows CardSpace. Please check the event log for more details." The event log indicates that the previous activation of the UI is still pending (I believe hung, waiting for user's response). If Password Safe is not running then the CardSpace UI runs fine.