This is probably not a new topic, and I have found some threads that talk about it, but nothing that hits the nail on the head and answers why the problem occurs.
When you are using a scheduled scan in NIS 2009 (not idle scan) and you schedule a scan task, it puts an entry in the Windows Task Scheduer. A task there must point to an executable. Normally this works fine.
But every once in a while, some update of NIS seems to put the new, updated executable in a different folder path, and the existing scheduled task then begins to fail. I see this on all my 4 PCs, and many of my clients.
The solution is simple: go into Task Scheduler, remove the task, go into NIS and reschedule. Simple, eh?
But WHY IS THIS HAPPENING! It never did before NIS2009. Very annoying...