Webcam images not updating

I've had a good look around to find a solution to this, but it seems people either have the webcam module working perfectly or not at all.

I'm using my gallery to collate a good few webcams from a number of sources and I've found that some of them simply do not update.

When adding, the webcam image is collected and updated fine. As a test, I've left some alone after the initial load and I've seem the thumbnail updating without the larger image changing or nothing at all.

If I make an edit to change the title or add keywords to the image, it never updates at all.

How does the update mechanism work? Is there a cron job I need to run or is it based on the age of the last collected image when it is looked at?

Any ideas to help me troubleshoot this one?

Martin
Darksnow.co.uk