Thanks, bjm. I can only remember this happening a couple of times in the recent past, both times on the laptop and both times after several days switched off. Normally, as with the PC, which is normally on daily, I just click on the "Vault is Closed" button first time I use it and/or after hibernation, and the password window appears.
Having said that, I was recently away for about 10 days with the PC switched off and when I got back and switched it on, I can't remember having this situation. It's not a problem if it's normal, just extra key strokes to get in.
Ian