Vista - Task scheduler problem

Happened a few times recently.....

I return to my laptop and there is an error on screen saying that task
scheduler has stopped working and something about DEP.

I just opened TS via computer management and I get an instant message (not
MSN!)....
Catastrophic failure (exception from hresult 0x8000ffff (E_Unexpected))
This is accompanied by another that says....
An error has occurred for task reminders - Jay. Error message: The specified
account name is not valid.

Any ideas?

I get these in the system event log:
Task Scheduler service failed to launch tasks triggered by computer startup.
Additional Data: Error Value: 2147549183. User Action: restart task
scheduler service.
and
The Net.Msmq Listener Adapter service depends the following service: msmq.
This service might not be installed.

These entries appear daily but not at the same time (5.30pm or 6.30pm or
7.30pm)

I seem to have several tasks (all unknown to me) that stopped/started around
the time tonight's errors occurred.

Hotstart (running)
NAPStatus (stopped at same time hotstart started)
Reminders - Jay (last run succeeded at same time other 2 stopped/started)

The above could be coincidental as I rebooted around this time.

Help please.