I have a feeling it has to do with server load. As you probably know, http by design can only handle one file per connection, so it connects in, gets the html, processes it, and opens new connections for each of the images on the page. There are some settings you can do that allow for more extended caching in some browsers to not download the images as much, but the basic issue if I was to hazard a guess, is that with somewhere upwards of 30 or more connections per page load, and say 50 people loading a page, that's 150 connections in a short time frame. The problem is intermittant enough that I would imagine that to be the case. There are plenty of times it seems to 'stick' trying to load.. I stop and reload and it pops right up.