All

I am having some trouble uploading some new product images to my site. I have uploaded lots in the past and never had any trouble however I have just uploaded a new set and am now having trouble getting some of them to be viewable. I have checked all the permissions (and tried setting them all to 777 just to be sure) and the files are viewable on my local system (so they are not corrupted in some way) but some just cannot be seen. I am not sure if it is helpful but two links are below (one works and the other does not) - any ideas where to start with this problem?

NOT VIEWABLE
http://www.specialdayinvitations.co.uk/images/7N475.jpg

VIEWABLE
http://www.specialdayinvitations.co....es/7N310-2.jpg

I just cannot see what might be wrong - it is not zen cart specific but appears to relate somehow to the files on my server and.or the browser. I am at a loss! Please help!

The images directory is (temporarily viewable).

Thanks

Gary