NIS stopped doing scheduled full scans

Hi there,

I have NIS (21.7.0.11) running on XP Pro SP3 which has full scans scheduled for every Monday (during the night).  If I am to believe it's 'History' log, the last full scan it did was on 27th April, hence it failed to do scheduled scans on 4th and 11th May.  Absolutely nothing of which I am aware has changed, in particular not any NIS settings.  The machine has been running continuously during this period, and continues to do one or two Quick Scans every day.  The configuration settings for the weekly full scans remain as they should be.

Any thoughts as to why the scheduled scans have stopped happening, and what I can do to get them back?

Kind Regards,  John