Your question is a little unclear. Does this module generate or modify the HTML with the image tags in it, and have you confirmed that the image tags are correct? Does it handle requests for images? It doesn't look like it does.

If the module itself isn't sending bad HTML and doesn't handle image requests, then it can't be responsible for the problem. Usually this kind of random failure has to do with browser bugs related to pipelining or keep-alive connections. Check general apache resources for possible config changes that might help.