[Zope] images are not found when zope is server through IIS

[CLAIN Jephte]

hello,

before I bang me head to figure out what is happening, I wonder if one
of you has this problem:

Zope is running on Windows NT with pcgi through IIS.
I use the LocalFS product to serve images.

http://mysite.com/Zope.pcgi/FS/photo.gif

doesn't work: photo.gif is not found. however, 

http://mysite.com:8080/FS/photo.gif

works as expected: the image is found and displayed correctly. 
Note that this seems not to be related to the LocalFS product, as no
images are shown in the management screens, they are not found neither.
the funny part is this problem only occurs for images. All other objects
(methods, documents, etc...) are always found

Any ideas?

regards,
Jephte CLAIN