Adding a thumbnail to a Gallery Thread

I have changed part of my thread so I want to update the thumbnail but every time I add my image address it bounces and doesn't update, maybe an administrator can help me? It has happened before, and I've been able to do it before too so just wonder if there's something Im doing wrong.

Using Metropol Upload services too if that helps!

It seems to work for me, make sure a) you have an image thats the right dimensions (176x99px) and b) Don't uses spaces in your filenames as it adds %20 for the spaces which can confuse things sometimes, best to use _ or - if you need the spacing.

Best of luck

Fab, the spacing was the issue, the name had 4 %20's in it!! So I've changed it and its worked!! Thank you so much!