Can you attach a copy of the page so I can take a look. Is it possible it is related to the login information they are using? Maybe ask what they are using to login in order to reproduce it. The key is figuring out how to reproduce the problem in order to debug and fix it.
I don't see a problem when I go to that page, but I suppose I might not even know it if a plugin wasn't loading because I don't know what the page is supposed to look like to begin with.