[Zope] image/gif objects sometimes not rendering

Hello, On some browsers, eg MSIE 6, some of my images simply do not appear on the browser screen. ( Or sometimes they do and sometimes not.) The URLS to the image are hard-coded and do not use aquisition. That is, I use: <img scr="/Images/imageName"> rather than <img src="ImageName"> I mention this last point because I have seen references to aquisition/caching issues affecting image rendering. The images are GIF files. I am using Zope 2.6.1 So something is happening. I am hoping someone has seen this and can give me some tips. Thanks much, David