More image problems...different method

Hi,

I have read through older posts about images. I couldn't find mentionof
this so....

My images are being served from a different webserver to cut down
repetition and disk usage. But I am using a rewrite rule for the images
as they are normally served dynamically.

This has worked in the past but no images are being shown now. If I
view the properties for an image in Firefox the image alt tag says
'can't display the image because there is an error'. Has anybody with
images not showing checked this as this may help to understand the
problem? I had this error before when I wasn't ouputing the image
correctly but this is resolved as far as I can tell now.

My usual image fetching php script relies on CURL. I read the remote
source and then echo the contents after echo'ing the content-type
header and content-length header. A parameter is passed for the correct
item. But my rewrite rule makes it look like it's served from a static
location which shouldn't interfere with froogle.

This is the headers I write out
header("Content-type: image/jpg");
header("Content-length: $size");

Ta.