Zope problem

[Seb]

Hello,

I've got a big (and very strange problem) using Zope (I've posted here
because I cannot find any "good" explanation).

On my PLONE web site after several minutes, the server makes mistakes when
it sends pictures and then even if the page looks ok, pictures are placed on
wrong positions.

My server provider said it is a bad configuration of a proxy but it happens
with 3 different internet providers.

If you have any suggessions I'll be happy

Regards

Sebastien VINOT