Yes it works on FF but not with IE6 or IE7 with exactly the same pdf and the same URL.

The hosting company this site is on charges to increase the memory_limit so I don't want to do this unless I'm sure it's the problem and if it's working in FF could this really be the problem?

I've set up a test page you can look at if want to see what happens with the different browsers. There is a link to a 2 page pdf and a link to a 4 page pdf. Clicking 'Print Photo Sheet' produces the pdf. (Having now set it up to open the pdf in a new window, I'm getting an Error No 6 in IE, rather than the Cannot find server or nothing at all that I was getting before). Most of the images are around 50kb or less, so I can't see that the number of images could be causing the problem?

http://www.genmaint.co.uk/pages/test.php